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GAS TORCH 

AND 

THERMIT WELDING 



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PUBLISHERS OF BOOKS FOP^ 

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GAS TORCH 

AND 

THERMIT WELDING 



BY 

ETHAN yiALL 

Editor American Machinist 

Member American Society of Mechanical Engineers, Society of Automotive Engineers, 

American Institute of Electrical Engineers, Franklin Institute, American Welding 

Society. Author of Manufacture of Artillery Ammunition, United States 

Artillery Ammunition, United States Rifles and Machine Guns, 

Broaches and Broaching, and Electric Welding. 



First Edition 



McGRAW-HILL BOOK COMPANY, Inc. 

NEW YORK: 370 SEVENTH AVENUE 

LONDON: 6 & 8 BOUVERIE ST., E. C. 4 

1921 



^r^2c'^- ^■ 



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Copyright, 1921, by the 
McGRAW-HILL BOOK COMPANY, Inc. 



MAR "8 1921 
0)CU608790 



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PREFACE 

The beginner, the practical worker, the student and tlie 
engineer, will find in this book a great amount of information 
regarding gas-torch and Thermit welding practice and equip- 
ment. No toil or expense has been spared to gather material of 
real and lasting value. Shops have been visited and data and 
photographs obtained first hand. Practically every book on 
welding has been carefully scrutinized for helpful suggestions. 
The services of experts have been engaged to give the results of 
long practice and research in their special lines. Each and 
every plan known to the experienced editor has been employed 
to give the reader the highest possible grade of information. 

The historical references have been cut to the barest state- 
ment of facts as we have been able to obtain them, yet they are 
ample enough to give the inquiring mind the genesis of each 
class. Foreign methods and equipment have not been touched 
upon, except in a few instances, because such treatment would 
add too greatly to the bulk of this work, without adding an 
appreciable amount to its real value, since the methods and 
standard equipment here are, in general, far in advance of 
anything similar elsewhere. 

Great care has been taken to indicate the sources of informa- 
tion and to give the names and addresses of the makers of equip- 
ment shown. It is believed that every well known maker of this 
class of welding apparatus in the United States has been men- 
tioned at least once in these pages. This has not been done 
with any idea of advertising them, but because it is information 
every reader is entitled to have without the necessity of making 
a separate search for it. 

Of course no recommendations regarding the best apparatus 
to use are made in any case. As in any other line, improvements 
are being constantly made, but in regard to newly invented or 
unknown equipment the seller should be made to prove his case 
before an investment is made. Apparatus which does not meet 



vi PREFACE 

the present day requirements, soon drops out of sight. It is a 
good plan for a prospective purchaser of equipment to consult 
some well established firm which is not afraid to advertise its 
product in open competition. Such a firm will see that its 
equipment is properly installed and works .satisfactorily. 

Ethan Viall. 

New York City, 
November, 1920. 



TABLE OF CONTENTS 
PART I— GAS TORCH WELDING. 

CHAPTER I 

PAGE 

History and Uses of the Gas Torch 1- 8 

Meaning of * ' Autogenous ' ' and the Term ' ' Gas Torch ' ' 
Welds — The Oxy-Acetylene Gas Torch — Used for Both Weld- 
ing and Cutting — Hydrogen Gas — Thermalene Gas — Blaugas — 
Drigas — Illuminating Gas — Benzine or Benzol Vapors — Ex- 
plosive Limits of Welding Gases — The Field of Gas Torch 
Welding and Cutting. 

CHAPTER II 

TuE Production of Welding Gases — Oxygen and Hydrogen. ... 9- 25 
Oxygen by the Liquid Air Process — Oxygen and Hydrogen by 
the Electrolytic Method — General Principles of the Elec- 
trolytic Method — Details of the Davis-Bournonville Electrolyzer 
Cell — The International Oxy-Hydrogen Generator — The Levin 
Type of Generator. 

CHAPTER III 

Acetylene and Medium, or Positive, Pressure Generators.... 26- 40 
Acetylene — Acetylene Cylinders — Acetone Injurious to a 
Weld — Estimating Amount of Acetylene — Types of Acetylene 
Generators — The Positive Pressure Generator — The Davis- 
Bournonville Tj'pes — The Buckeye Carbide-Feeding Mechan- 
ism — The Portable Pressure Type — Approximate Dimensions 
and Weights of Acetylene Generator Sets. 

CHAPTER IV 

Low Pressure Acetylene and Thermalene Generators 41- 53 

Low Pressure Generators — The Oxweld Duplex Generators — 
Thermalene Generators — How the Cartridge is Packed — Action 
of the Thermalene Generator — Some Advantages of Thermalene. 



viii CONTENTS 

CHAPTER V 

PAGE 

Gas Torches Used for Welding 54- 73 

Types of Torches — The Davis-Bomnouville Positive Pressure 
Torch— The Prest-0-Lite Torch — The General Welding Co. 's 
Torch — The Imjaerial Torches — Calculating Amount of Gas 
Used — The Rego Welding Torch — The Oxweld Low Pressure 
Torch — The Messer Torch — The Thermalene Torch. 

CHAPTER VI 

Gas Cutting Torches 74- 94 

The Davis-Bournonville Cutting Torch — The Oxweld Cutting 
Torch — Cutting Data — The Messer Torch — The General 
Welding Co. 's Torch — Imperial Torches — Caibo-Hydrogeu 
Torches — Airco-Vulcan Combination Torch — The Rego Torch — • 
The Milburn Combination Torch— The Torchweld Torch — The 
Davis-Bournouville Underwater Cutting Torch. 

CHAPTER VII 

Gas-Pressure Regulators and Working Assemblies 95-115 

Oxweld Oxygen Regulators and Gages — Other Regulators and 
Gages — Tank and Hose Colors — Regulator Adaptors — Con- 
necting Up an Outfit — The Two Types of Tank Connec- 
tions — Characteristics of the Oxy-Acetylene Welding Flame — 
Imperial Three-Way Outfit — Lighting the Oxweld Low Pres- 
sure Torch — Characteristics of the Oxy-Hydrogen Flame — 
Characteristics of the Hydrogen-Compressed Air Flame — Char- 
acteristics of the Oxy-Illuminating Gas Flame. 

CHAPTER VIII 

Gas Torch Welding and Cutting Outfits 116-130 

Typical Oxy-Acetylene Cutting Unit — Manifolds — Complete 
Working Outfits — Back Pressure A'alves — Lead Burning — 
Method of Connecting Outfits for Various Gas Combinations — 
A Gas Flow Indicator. 

CHAPTER IX 

Learning to Weld with the Gas Torch 131-153 

The Way to Hold a Torch — Torch Motion — Welding Two 
Plates — Allowing for Seam Contraction — Using the Welding 
Rod — Various Welding Jobs — Sources of Trouble — Built-Up 
Welds — Vertical Welds — Filling Up a Hole — Forming Bosses 
or "Putting on" Metal — Practicing on Gear Teeth — Welding 
Backward — Lead Burning. 



CONTENTS IX 

CHAPTER X 

PAGE 

Makixg Allowance for Expansion and Contraction 154-168 

Action of Metal When Heated — Using Heating Torches — 
Cooling Work — The Wiederwax Preheater — Suggestions Ee- 
garding the Welding of Gratings and Pulleys — Automobile 
Cylinder Work. 

CHAPTER XI 

Welding Various Metals and the Fluxes Used 169-186 

Properties of Metals — Conductivity and Oxidation — Vaporiza- 
tion of Substances— Separation of Elements — Welding Various 
Metals — Welding Aluminum — Filling a Large Hole — Brass 
and Bronze — Cast Iron — Cast Iron to Steel — Copper — Copper 
to Steel— Lead — Malleable Iron — Monel Metal — Nickel — 
Steel — Special Steels — Manganese Steel — Nickel Steel — Vana- 
dium Steel — Chrome Steel — Wrought Iron — Galvanized Iron — 
German Silver — V/hite Metal Castings — Silver — Gold. 

CHAPTER XII 

Examples o? Welding Jobs 187-220 

Preparing for Welding — Examples of Special Jobs — Welding 
Broken Machine Tools — Preparation for Locomotive Frame 
Welding — Cooling Devices — Rail Bonding — Rudder Frame 
Welding — Large Engine Cylinder Work — Welding High Speed 
Steel Tips to Low Carbon Shanks for Shop Tools. 

CHAPTER XIII 

Welding Jigs and Fixtures 221-238 

Holding Pipe for Welding — A Welding Table — V-Blocks for 
Holding Shafts — Jig for Holding Crankshafts — An Adjust- 
able Crankshaft Jig — Crankcase Devices — Motorcycle Mani- 
fold Jig — Sheet Metal Roller Jig — Sheet Metal Cjdinder 
Jig — Apparatus for Welding Cylinder Ends — Welding Poison 
Gas Containers — Liberty Motor Work — Fixtures for Motor 
Manifolds. 

CHAPTER XIV 

Welding Machines 239-256 

The Duograph — How the Duograph Works — Drum Welding 
Machine — Light Seam Welding Machine — Machine for Weld- 
ing Oblong Seams — Tube Welding Machines— Tube Welding 
by the Oxy- Acetylene Process — Arrangement of Rolls on a 
Tube Welding Machine. 



X ~ CONTENTS 

CHAPTER XV 

PAGE 

Cutting with the Gas Torch 257-277 

Correct Cutting Position — Starting a Cut — Examples of Good 
and Bad Work — Blowing a Hole Through a Plate — Using 
Various Devices — Flame Control — Making a Ladle Hook — 
Costs of Some Cutting Jobs — Cutting Cast Iron — Torches 
Made to Preheat the Oxygen— Cost of Oxy-Hydrogen Cutting. 

CHAPTER XVI 

Cutting Machines 278-294 

Cutting with Hand Machines — The Radiagraph — The Railo- 
graph — Circular Cutting— The Magnetogi-aph — The Camo- 
graph — The Great Western Cutter — The Pyrograph — The Uni- 
versal Cutter — The Oxygraph. 

CHAPTER XVII 

Welding Shop Layout, Equipment and Work Costs. 295-313 

The Equipment Necessary for a First Class Shop — Layout of 
the Oxweld Shop — Keeping Track of C^osts — The Oxweld Cost 
Form — The Imperial Cost Form — Carbon Burning — Safety 
Rules for Gas Torch Workers — U. S. Railway Administration 
Autogenous Welding Rules — Strength of Oxy-Acetylene Welds. 

PART II— THERMIT WELDING. 

CHAPTER I 

Thermit Welding: Its History, Nature and Uses 317-321 

What Thermit Is — Temperature and Characteristics — IMastic 
and Fusion Methods — Kinds of Thermit Commonly Used — 
Plain Thermit— Railroad Thermit— Cast Iron Thermit. 

CHAPTER II 

Making Plastic Process Welds 322-332 

Uses of the Three Varieties of Thermit— A Pipe Welding Out- 
fit—How the Mold is Used— Placing and Igniting Thermit- 
Removing the Mold— Cost and Strength of Pipe Welds. 

CHAPTER III 

Fusion Welding of Heavy Sections 333-357 

Type of Crucible Used for Thermit Welding— Tapping a 
Crucible — Life of Lining Prolonged With Magnesia Tar- 
Crucible Ready for Baking— Thimbles— Application of Fusion 
Welding— Wax Pattern Molds— Ramming the Mold— Preheat- 
ing the Mold — Igniting Thermit — Amount of Thermit Needed 
for Welds — Locomotive Frame Work — Other Railroad Work. 



CONTENTS xi 

CHAPTER IV 

PAGE 

Welding Crankshafts, Mill Pinion Tektii, Etc 358-373 

Y-Bloeks for Welding Crankshafts — Defects that Frequently 
Occur — Inaccuracy of Alignment Explained — How to Locate 
Minute Cracks — Welding New Teeth in "Large Pinions — Mak- 
ing a Wax Tooth Pattern — Another Method of Welding Pinion 
Teeth — Preheating Large Work. 

CHAPTER Y 

Welding New Necks on Large Pinions and Other Heavy Work 374-390 
Two Methods of Working — Foundation and Heating Arrange- 
ments — Constructing the Mold for a Large Roll or Pinion — ■ 
Amount of Thermit Required — Treatment When a Cope is 
Used — Alternate Method — Marine Repairs. 

CHAPTER VI 

Rail Welding for Electric Systems 391-402 

Rail Joint Work — Adjusting the Insert Between the Rails — ■ 
Adjusting the Mold — Preheating — The iJse of Thermit Addi- 
tions — The Grinding Machine. 

CHAPTER VII 

Welding Compromise Rail Joints 403-412 

Kinds of Compromise Joints — Using a Rail Section for a Pat- 
tern—The Clark Joint— Modified Clark Joint— Welded Cross- 
over — Motor Case Work — Car Truck Work. 

CHAPTER VIII 

Welding Cast Iron and Other Parts 413-425 

Thermit to Use for Cast Iron — Examples of Cast Iron Welds — - 
Welding High Speed to Machinery Steel — Cost of Thermit Ap- 
paratus — Preheaters for Thermit Work — Cost of Materials and 
Apparatus for Pipe Work. 

Index 426 



PART 1-GAS TOECH AVELDING 



GAS TORCH AND THERMIT WELDING 



CHAPTER I 
HISTORY AND USES OF THE GAS TORCH. 

According to common usage, the term "autogenous weld- 
ing" is erroneously applied only to hot gas flame fusion welds. 
The gas combinations used for the production of the hot flame 
for welding or cutting are oxy-acetylene, oxy-hydrogen, oxy- 
thermalene or any combination that will produce sufficient heat, 
and is applied by means of a torch or blow-pipe. The welds so 
produced are strictly fusion welds, as no pressure or ham- 
mering is employed to effect the union. The word ' ' autogenous ' ' 
means "self-produced" or "self-generated," that is, joined with 
the same metal, and as such applies equally to hot gas flame, 
electric arc or thermit welds, although as just stated, the present 
custom is to apply the term generally to hot gas flame welds. 
However, owing to the wide field that the term "autogenous" 
really covers, and to the looseness with which it is often applied, 
we prefer to use the term "gas torch" in connection with 
Avelding and cutting by means of the hot gas flame. 

While the use of a blow-pipe or torch in some form was 
known to the ancients, the high temperature gas flame is a 
development of the last quarter of a century. The more com- 
monly known gas combination is oxy-acetylene. Acetlyene 
(CoHo) was discovered by Edmund Davy in 1836, but it re- 
mained only a laboratory gas until T. L. Willson of North 
Carolina and H. Moisson, the Frenchman, developed commercial 



2 GAS TORCH AND THERMIT WELDING 

methods of producing calcium carbide (CaC^) in large quanti- 
ties in 1891-92. In 1895 Le Chatelier read a paper before the 
Paris Academy of Sciences in which he stated that : ' ' acetylene 
Inirned with an equal volume of oxygen gives a temperature 
which is 1000 deg. C. (1800 deg. F.) higher than the oxy- 
hydrogen flame. The products of the combustion are carbon 
monoxide and hydrogen, which are reducing agents." Further 
along he said: "this double property makes the use of acety- 
lene in blow-pipes of very great value for the production of 
high temperatures in the laboratory." This statement of Le 
Chatelier is especially noteworthy, since he set the ratio of the 
gases at equal volumes, and not at the theoretical proportion 
of 2^ volumes of oxygen to 1 of acetylene. 

The application of the oxy-acetylene gas torch to metallic 
welding dates experimentally from 1901, and industrially from 
1903. Edmond Fouche, of Paris, who did considerable experi- 
menting in conjunction with Picard, is generally credited with 
having devised the first really practical and safe torch. In 
February 1904 Fouche sent two of his torches to Eugene 
Bournonville, of New York, with which the latter repaired a 
machine that was still in use years later. The Fouche and 
Picard torch first developed, used both oxygen and acetylene 
under high pressure. There proved to be serious objections to 
this, and Fouche next produced the low pressure or injector 
type of torch which employed only the oxygen under high pres- 
sure. Following these was the Gauthier-Ely positive pressure or 
medium-pressure type which used both gases under moderate 
and independent pressures. This type was later brought to 
the United States by Augustine Davis and Eugene Bournon- 
ville in 1906. During this year Bournonville designed the first 
acetylene pressure generator produced in connection with the 
oxy-acetylene process. 

In 1905 and 1906 considerable Avelding work was done but 
the process was handicapped by the inadequacy and poor 
quality of the oxygen then obtainable, and also by the im- 
perfect knowledge and technique necessary to good work. In 
1902, Carl Linde patented in England a process for liquefying 
air and producing oxygen and nitrogen. In 1906 a plant for 
the production of oxygen by the Linde process was established 
in Buffalo, N. Y. From that time on, oxygen plants of various 



HISTORY AND USES OF THE GAS TORCH 3 

kinds have constantly increased in number and the commercial 
production of oxygen of good quality has been a great factor 
in the development of gas torch welding. 

At first, operations were limited to the simplest repair work 
on iron or steel. As the apparatus was improved and the 
efficiency of the welders increased, the field widened. New 
uses have been found for the process and the range of metals 
coming within its scope has steadily expanded. It has its 
limitations, however, which will be pointed out elsewhere. 

Used for Both Welding and Cutting-. — In addition to weld- 
ing, the oxy-acetylene flame, as well as a number of others, 
is applicable to cutting. In fact so closely allied are welding 
and cutting in this field, that an operator is usually called 
upon to do both many times in a day's work. Cutting by 
means of an oxygen jet was first made commercially possible 
by Jottrand, who took his basic patent in 1905. 

Aside from the manual operation of welding or cutting 
torches, a large number of machines have been designed. These 
range from simple wheel or radius attachments for the torch 
itself, to huge automatic pipe making machines or others of a 
complicated nature. 

The oxy-acetylene flame consists of two parts, a small inner 
luminous "cone" which is bluish white in color, and a larger 
enveloping non-luminous flame. The temperature at the apex 
of the cone is estimated to be about 6300 deg. F. This heat is 
not surpassed by any burning gas with the possible exception 
of thermalene, for which 6500 deg. F. is claimed. 

For welding purposes the high efficiency of acetylene is due 
to its high carbon content and to the fact that it is endothermic, 
that is to say, heat-absorbing in its formation. Energy 
stored up in formation is given off again in the form of 
heat by the acetylene upon dissociation. It is calculated that 
of 1475 heat units in a cubic foot, 227 are due to the mere 
breaking up of the gas. "While theoretically two and one-half 
volumes of oxygen are needed to completely burn one volume of 
acetylene, the ratio in which the gases are employed in prac- 
tice is about one volume of oxygen to one volume of acetylene. 
The flame yielded by such a mixture is the correct one, or the 
so-called "neutral" flame. By increasing or decreasing the 
proportion of oxygen, flames known as either oxidizing or 



4 GAS TORCH AND THERMIT WELDING 

reducing may be obtained, tbe appearance of the cone changing 
as the proportions are modified. 

While the use of oxy-acetylene for welding is more commonly 
known than any other combination, there are several gases, which 
when mixed with oxygen, will produce more or less satisfactory 
welds. Some of them are to be preferred to acetylene for 
certain cutting purposes. The better known gases are described 
as follows, it being understood that they are to be used with 
oxygen. 

Hydrogen gas is a chemical element which exists in nature 
in great quantities in various chemical combinations. The most 
common is its union with oxygen to form water (HoO). As a 
consequence, water is used as a basis for making both oxygen 
and hydrogen. Oxy-hydrogen welding was the first gas torch 
welding system employed, and it was used quite extensively 
until the introduction of the more advantageous system of weld- 
ing with oxy-acetylene. While hydrogen may be manufactured 
on the premises, it is also handled commercially in steel cylinders. 
In using this flame for welding there is an existing danger that 
the oxygen may unite with the metal causing it to be overheated 
or burnt. To prevent the burning of the metal, it becomes 
necessary to use a supercharge of hydrogen so that oxygen 
liberated within the flame will combine with the free hydrogen 
instead of with the metal. This, however, increases the size 
and decreases the temperature of the flame. The temperature 
of the oxy-hydrogen flame according to Kautny, can never go 
higher than the dissociation temperature of water, which is 
estimated at 2000 dcg. C. (3632 F.) For welding thin metal 
sheets hydrogen is practical on account of its comparatively 
low heat. The quality of the weld, however, decreases as the 
thickness of the metal increases. While theoretically only two 
volumes of hydrogen are required to one of oxygen, in actual 
practice when employing an oxy-hydrogen toreh, it is necessary 
to use four or five volumes of hydrogen to one of oxygen in 
order to insure a non-oxidizing flame. This in itself is a waste- 
ful process, since the maximum heat obtained is limited to the 
amount produced by combining two volumes of hydrogen to one 
of oxygen. For heavy cutting it is preferred to acetylene on 
account of its longer flame. It is also used extensively for lead 



HISTORY AND USES OF THE GAS TORCH 5 

burning, preheating, soldering, brazing, annealing, special forg- 
ing or rivet heating and a number of other things. 

Tliermalene is one of the latest gases to be produced. It is 
the discovery of Linus Wolf, Zurich, Switzerland, and it is 
handled in this country by the Thermalene Co., Chicago Heights, 
111. It is a combination produced by the decomposition of 
calcium carbide and hydrocarbon oils, the heat generated by 
the carbide being used to vaporize the oil. It is used for either 
welding or cutting. 

Blmigas is a liquid under pressure. It is the discovery of 
Herman Blau and it is made from gas oil, a product of the 
oil refineries. It probably has the low^est explosive range of 
any gas used for illuminating purposes, the range being about 
4 per cent wiiile that of coal gas is about 13 per cent. Like 
coal gas, however, it is little used for welding, though sometimes 
used ft)r cutting. Blaugas is marketed in steel cylinders having 
the equivalent of 1300 cu.ft. of city gas, by the American 
Blaugas Corp., New York. Its largest field is for cooking and 
lighting purposes where coal gas is not readily obtainable. 
Owing to its portability it may be used to advantage for pre- 
heating work. 

Drigas is a light oil gas, which is a vapor under pressure. 
It is sold in steel cylinders of about 150 cu.ft. by the same 
concern handling blaugas. It is especially good in combination 
with oxygen for cutting metal from 1 to 12 in. thick, and is 
also considerably used for preheating. Its explosive range is 
about ^ that of coal gas, and it is non-poisonous and non- 
asphyxiating. 

Illuminating Gas (coal gas or water gas) can only be used 
for welding very thin pieces owing to the low temperature of 
the flame. It may, however, be used for preheating or cutting. 

Benzine or Benzol Vapors have the same properties, approxi- 
mately, as blaugas. The temperature is a little higher than 
that of illuminating gas, but much lower than acetylene. It 
is only used for welding under special circumstances. 

While a number of gases, which are used with oxygen, have 
been mentioned, only the production and use of hydrogen, 
acetylene and thermalene will be described, along with that of 
oxygen. 

Explosive Limits of Welding Gases. — In order to be ex- 



6 GAS TORCH AND THERMIT WELDING 

plosive, a combustible gas or vapor must be mixed with a 
certain amount of oxygen or air, the proportions of the mix- 
ture ranging between certain limits depending on the char- 
acter of the fuel. Any figures showing these explosive limits 
of the gases can only be approximate at best, since so many 
things enter into the calculations, such as the purity of the 
gas, means of ignition, temperature, pressure, and so on. In 
general, the mixture that has just enough oxygen for com- 
plete combustion of the fuel gives the highest pressures and 
temperatures, and very nearly the highest speed of ignition. 
If the proportion of oxygen (air) is increased beyond, or 
decreased from, the theoretical proportion, the maximum 
pressures and temperatures are lowered and the speed of 
ignition decreases until at certain upper and lower limits the 
mixture ceases to be explosive, and only slow combustion can 
occur. 

The figures here given are believed to be a fair average of 
those given by the various authorities. The explosion is sup- 
posed to be caused by an electric spark, at atmospheric pressure 
and a temperature of about 65 deg. F. 

Acetylene — 3 per cent gas plus 97 per cent tiir to 55 per cent gas 
plus 45 per cent air, or a range of 52 per cent (one writer says 73 
per cent gas plus 27 per cent air). 

Blangas — i per cent gas plus 96 per cent air to 8 per cent gas 
plus 92 per cent air, or a range of 4 per cent. 

Coal Gas — 6.5 per cent gas plus 93.5 per cent air to 19.5 per cent gas 
plus 80.5 per cent air, or a range of 13 per cent. 

Drigas — 4 per cent gas plus 96 per cent air to 8 per cent gas plus 
92 per cent air, or a range of 4 per cent. 

Hydrogen — 10 per cent gas plus 90 per cent air to 66 per cent gas 
plus 34 per cent air, or a range of 56 per cent (one writer says 6 
per cent plus 94 per cent to 72 per cent plus 28 per cent). 

Thermalcne — 12 per cent gas plus 88 per cent air to 30 per cent 
gas plus 70 per cent air, or a range of 18 per cent. 

The ignition temperatures of some of the gases, at at- 
mospheric pressure are: Acetylene, 760 to 820 deg. F. ; city 
gas, 1100 deg. F. ; hydrogen, 1075 to 1100 deg. F. 

According to McCormack, the cu.ft. per pound of gases 
M'as calculated for the specific gravity and found to be : Acety- 
lene, 14.8 cu.ft. ; coal gas, 24.3 cu.ft. ; hydrogen, 192.4 cu.ft. ; 
thermalene, 13.97 cu. ft. 



HISTORY AND USES OF THE GAS TORCH 7 

The Field of Gas Torch Welding and Cutting. — In a general 
way, the field of the gas torch welding and cutting may be 
outlined as follows, though some of the applications enume- 
rated are more advantageously done by other methods. This 
is especially true with reference to the welding of heavy sec- 
tions which should, as a rule, be done with thermit. 

Airplane Construction. — Welding water jackets to cylinder, valve 
cages to cylinder, of manifolds (intake, exhaust, and cooling), flanges 
to the manifold connections, spark plug thimbles, tubular sections for 
frame, splice plates, sockets to frames, aluminum crank cases, water 
tank. 

Automobile Industry. — Welding rear axle housings, defective gears 
and pinions, manifolds, shafts, steering posts, automobile bodies 
(aluminum and steel), tubing used in wind shields, etc., crank cases, 
transmission cases, wheels which are made of stamped-out parts, 
mufflers, valve stems to valves, rims, repairing crank shafts, frames, 
extending frame to make a truck out of a car. 

Copper Plate. — Welding manifolds, flats, kettles, vats, tanks, copper, 
stills and chemical ware. 

Electric Raihvay. — Welding of bonds, worn boxes, riotor housings, 
building in teeth of defective pinions and ge:irs, reclaiming of broken 
trucks, welding air receivers on air-brake system, steel trolley wires, 
side frames. 

Forge Shop. — Welding ornamental iron, complicated parts. 

Foundries. — Steel foundry: Welding up of blowholes, porous spots, 
blocks, cutting of risers, gates and heads ; welding moldings which 
are cast in parts. Cast iron foundry : Reclaiming castings. 

Lead Burning. — Burning of connectors on storage batteries, bat- 
tery repairs, lead linings in vats, tanks, etc., lead-pipe joints. 

Piping and Gas Main WorJi. — Welding of steam, air, gas, oil, and 
water lines, welding for high pressure gas distribution, annnonia 
systems. Fittings, such as T's, Y's, S's, crosses, which are cut and 
welded on the job, meter connections for houses, traps, drip pots. 

Plate Welding.^— Anmwma receivers, generators, air receivers, tanks 
for oil, vacuum driers, digesters, vats, steam driers, tanks of all kinds 
which are to be subjected to heat and pressure, plate assembly work 
for gas manufacture by-products, recovery work, stills. 

Poicer Plant Maintenance. — Building up worn or broken parts, weld- 
ing of cylinders, pistons, valve chests, etc. Welding of steam lines, 
of pump castings broken in service. Repairing of flywheels. 

Railroad Repair. — Firebox repairs (including patches), replacing 
side sheets, welding in flues, cutting off rails, mud rings, welding 
cracked steam chest, valves, cross-heads, cylinders, building up worn 
pins, cutting out links, irregular shapes of steel, filling worn spots on 
wheels, welding spokes, cutting and welding up locomotive frames. 
Welding together parts of car seats, chair and window frames. Re- 



8 GAS TORCH AND THERMIT WELDING 

claiming bolsters, couplings, slotting forged engine rods; building up 
frogs and diamond crossings, scrappings. building steel cars. 

Rolliny Mill. — General repair of engines, rolls, hot beds, plates, 
furnace equipment, fabricating open-beai"tli water jacket doors, re- 
claiming copper tuyeres, cutting up lost heats, cutting up "kindling" 
or scrap, bar stock, billets, plates. 

Sheet il/<:Yrt?.— Manufacture of metallic furniture, steel barrels, trans- 
former cases, range boilers, kitchen utensils, light air tanks, tubing, 
oil storage tanks. 

Shipyards. — Cutting of plates, channels, special sections, welding 
and reclaiming of broken parts of machinery and propellers, patching 
of hulls, stringers, building up of worn chocks. 

Small Arms Manufacture. — Reclaiming component parts, spot hard- 
ening of different parts, spot annealing. 

Structural Steel. — Cutting as applied to coping, splicing and fitting 
rails, channels, I beams and other sha]ies. Cutting holes for rivets, 
welding up misdrilled holes, cutting of all kinds of gusset splice plates, 
cutting wrecking, welding structural parts where riveting is not 
possible. 



CHAPTER II 

THE PRODUCTION OF WELDING GASES— OXYGEN 
AND HYDROGEN 

Oxygen is a gas which constitutes about 23 per cent by 
weight and 21 per cent by volume of the air we breathe, most 
of the other percentage being nitrogen, a gas which does not 
support combustion. Oxygen itself will not burn, but it is 
the greatest supporter of combustion known. It was probably 
discovered by Stephen Hales in 1727, though Priestly was the 
first to publish a description of it in 1774. The name ' ' oxygen ' ' 
was later applied to the gas by Lavoisier. Pure oxygen is 
colorless, odorless and tasteless. For welding work it is im- 
portant that the oxygen used be as pure as it is commercially 
possible to obtain it. The impurities which decrease its effi- 
ciency are usually hydrogen and nitrogen. 

There are three ways to produce oxygen commercially; by 
means of liquid air, by chemicals and by the electrolytic 
process. When oxygen is made by the liquid air process, 
there is a certain amount of nitrogen present. In the chemical 
methods, a number of impurities may cause trouble. By the 
electrolytic process, the impurity is hydrogen. 

Oxygen by the Liquid Air Process. — As a general rule, 
taking everything into consideration, it is far better for the 
average or small user to buy his oxygen from a reliable con- 
cern and not try to manufacture it himself. The oldest concern 
in this country making oxygen by the liquid air process is the 
Linde Air Products Co., with offices in New York City. Their 
cylinders are regularly furnished in two sizes of 100 and 200 
cu.ft. capacity respectively. They are charged to a pressure 
of 1800 lb. at a temperature of 70 deg. F. Customers are 
furnished cylinders free and pay only for the oxygen. Empty 
loaned cylinders are exchangeable for filled ones at stations in 
practically every city of fair size in the country. A 50 ft. 

9 



10 GAS TORCH AND THERMIT WELDING 

size of cylinder is obtainable for those whose requirements 
are very limited. A number of other concerns supply elec- 
trolytic oxygen for the market, the 100 cu.ft. cylinders being 
about 85 in. in diameter and 48 in. high, weighing approxi- 
mately 122 lb. when filled. Tlie average purity of oxygen in 
cylinders is about 99 per cent. 

Since the production of oxygen by the liquid air process 
is only applicable to large installations any detailed descrip- 
tion of the method would be out of place here. It is sufficient 
to say that in general, the process consists of first reducing 
the air to liquid form by means of the combined action of 
high compression and low temperature, and then separating 
the oxygen and nitrogen of which it is composed, by taking 
advantage of the different boiling points of the two. Under 
atmospheric pressure the boiling point of very pure liquid 
oxygen is — 182.7 deg. C. ( — 296.9 deg. F.) and of very pure 
nitrogen — 195.5 deg. C. ( — 319.9 deg. F.). This means a dif- 
ference in the boiling points of 12.8 deg. C, or 23 deg. F. 
These respective boiling points will, of course, vary under 
different pressures, and various degrees of purity, but tlie 
difference between the two is sufficient to allow of the nitrogen 
lieing vaporized in suitable apparatus and carried away before 
the oxygen vaporizes. 

The Chlorate of Potash Process. — Where circumstances 
make the chemical production of oxygen advisable, the 
chlorate of potash method is probably the most satisfactory 
at the present time. In this process chlorate of potash 
(KCIO3) and manganese dioxide (MnOo) are mixed together 
in the proportion of 100 to 13 parts (about 8 to 1). This 
riixture is placed in a retort filled as full as possible to exclude 
air. The retort is then heated and the oxygen is driven off. As 
the oxygen gas passes off from the retort it is conveyed through 
a cylinder or vessel containing sodium hydroxide (NaOH) 
which removes most of the impurities. The oxygen is then 
piped to a gasometer from Avhich it may be used direct or 
pumped into cylinders. A pound of the mixture is said to' 
produce about 4 or 4^ cu.ft. of oxygen. The manganese diox- 
ide is unchanged during the process. It is used because it 
enables the chlorate of potash to more readily give up its 
oxygen and at a lower temperature than without it. 



THE PRODUCTION OF WELDING GASES 



11 



An oxygen generator working on the general principles 
just outlined is made by the Macleod Co., Cincinnati, Ohio. 
This firm makes both a stationary and a portable type. A 
stationary type is shown in Fig. 1 and a portable one in 
Fig. 2. The generator, which consists of a furnace with retort, 
a scrubber for holding the purifying solution, and a receiver 




Fig. 1. — The Buckeye Chemical Oxygen Generating Set. 

for the gas, is quite convenient for small shops or garages 
where a limited amount of oxygen is used. It is quite possible, 
however, to fill tanks from these generators for storage pur- 
poses and immediate use if needed. An oxygen generator 
may be used in conjunction with a cylinder of dissolved acety- 
lene, or with a separate acetylene generator. Where portable 



12 



GAS TORCH AND THERMIT WELDING 



j]fenerators are used for both oxygen and acetylene, it is ad- 
visable to have the outfits on separate trucks so as to decrease 
danger should any leaks develop. 

The Buckeye generator is so made that it is adaptable to 
the use of wood, coal, coke or charcoal for fuel, or can be fitted 
with gas, gasoline, alcohol or oil burners. The portable type 
is shown fitted with a gasoline burner. The generators are 




Fig. 2. — Buckeye Oxygen Generator Mounted on a Truck. 



tested to 2^ times the maximum working pressure of 300 lb. 
Safety devices are provided so that it is safe for practically 
unskilled tenders. These generators are made in three sizes, 
with a capacity of 40, 60 and 100 cu.ft. of oxygen per hour. 
The weight of the portable type will range around 650 lb. 
and of the larger stationary type about 1600 lb. 



THE PRODUCTION OF WELDING GASES 13 

OXYGEN AND HYDROGEN BY THE ELECTROLYTIC 

METHOD 

The electrolytic process for the production of oxygen is 
more adapted to private installations than the liquid-air 
process. An electrolytic installation is flexible, and may be 
expanded so as to produce any commercial quantity of gas 
desired with very little attention. One big advantage of 
this process is that hydrogen is produced at the same time 
as the oxygen, and in many cases this hydrogen can be used 
to advantage for welding, cutting, or other purposes. 

As a rule, oxy-hydrogen for welding is less desirable than 
oxy-acetylene, but for some purposes, especially when there 
is an abundance of hydrogen available, it is very satisfactory. 
The heat produced by the oxy-hydrogen flame (about 2632 
deg. F.) is considerably less than that of the oxy-acetylene 
flame (about 6300 deg. F.), consequently it is commonly em- 
ployed for welding thin metals, lead burning or other work 
Avithin its heat range. As a general rule, oxy-hydrogen is good 
for welding 16-gage steel, or thinner, but should not be used 
on steel over ^ in. thick. As hydrogen contains no carbon, 
the weld is softer than with acetylene. Cast iron up to f in. 
in thickness may be successfully welded, as may also aluminum 
crankcases or alloyed metals. For cutting, however, oxy- 
hydrogen has a wide field, especially for heavy work. 

General Principles of the Electrolytic Method. — In an ele- 
mentary form, decomposition of water may be effected by 
passing an electrical current between two metallic poles, or 
electrodes, immersed in water. By the admixture of acid or 
alkali, forming an electrolyte, the resistance of the water is 
lowered to allow a large current of electricity to pass, pro- 
portionately raising gas production. Simultaneously with the 
passage of current, decomposition of water into its components, 
oxygen and hydrogen, begins. Oxygen, exhibiting positive 
electrical properties, is formed on the positive pole or "anode" ; 
double quantity of hydrogen is formed at the same time on 
the negative pole or ''cathode." The gases are immediately 
available, and by interposition of a suitable diaphragm be- 
tween the poles, are kept separate and led to their proper 
receivers. 



14 GAS TORCH AND THERMIT WELDING 

Tlic rapidity of decomposition, and consequently tlie amomit 
of gases evolved being in direct measui'C of the electrical 
current passing, there is alTorded convenient and economical 
means of producing commercial oxygen and hydrogen. The 
electrolytic solution increases in density as the action con- 
tinues. The volume of water dissociated is therefore replaced 
at regular intervals. 

Complete separation of the gases is desirable in order to 
insure their availability at high purity. This involves the 
use of a diaphragm, which, immersed in the solution, will 
allow passage of current between the poles and at the same 
time prevent mixing of gases. 

The production of oxygen and hydrogen being in respect 
to the amount of current passing, it is apparent that the voltage 
required to send the specified amount of electricity tlu-ough 
the electrolyzer is a measure of the efficiency of the apparatus, 
since, if the kilowatt-hour consumption is known, the gas pro- 
duction may be compared with it. Thus, there has been 
evolved the commonly accepted performance rating of any 
electrolyzer given in terms of cubic feet of gas produced per 
kilowatt-hour operation. 

The production of pure gases is very important. In the 
earlier types of water electrolyzers the requirements for pro- 
ducing gases of high purity were not understood, witli the 
result that means of purification of the gases after generation 
were necessary. Devices of this character have been found 
expensive to maintain and inefficient in action. Modern de- 
signs of electrolyzers are capable of delivering oxygen of about 
99 per cent, and hydrogen of equal or greater purity, so that 
the need for external purifying means no longer exists. 

On delivery from the electrolyzers the gases are conducted 
separately to a pressure regulating device which imposes equal 
pressures on both oxygen and hydrogen, thus equalizing the 
pressures on each side of the separating diaphragm. The 
gases are then passed to their respective gas holders, in which 
they are collected and stored at a few ounces pressure, l^pon 
the nature of service of the gases will depend the size of the 
gas holders, and the method of compressor control. 

If it is desired to compress the gases into cylinders for 
shipment, as in the case of a commercial plant, large gas 



THE PRODUCTION OF WELDING GASES 15 

holders are employed having capacity for, at least, a con- 
tinuous day's run of the electrolyzers. High-pressure com- 
pressors draw from these holders and discharge to a manifold 
to which the portable cylinders are connected. The pressure 
carried in the cylinders is usually 1600 to 1800 lb. per sq.in. 
Cylinders of 100 and 200 cu.ft. capacity will weigh about 85 
and 150 lb. respectively. 

There are many oxy-hydrogen producing equipments in- 
stalled in industrial establishments, the gases being utilized 
in various portions of the works. In the Davis-Bournonville 
installations, gas holders of moderate size are employed, their 
rise and fall starting and stopping the compressor motors 
'through automatic electrical control devices. 

The gases may be stored in stationary pressure tanks to 
a moderate amount, these being fitted with automatic regu- 
lators, so that when they are filled to capacity, the entire 
plant will be shut down. The gases are piped, where desired, 
through pressure lines, thus avoiding the replacement of empty 
cylinders. This method of installation is particularly desir- 
able for continuous welding and cutting operations, either by 
hand or mechanical means. Provision may also be made for 
charging portable cylinders for use in operations carried on 
at isolated points. 

Through the automatic control mentioned, the flexibility 
of an oxy-hydrogen generating and compressing equipment 
may be appreciated. The required amount of attendance being 
small, and needed only at regular intervals, continuous 24- 
hour operation of the equipment or intermittent service, if 
desired, is quite feasible and practicable. If maximum pro- 
duction is not desired, reducing the current passing through 
the electrolyzers will proportionately lower the volume of gas 
that is being generated. 

Details of the Davis Electrolyzer Cell.— For various reasons, 
electrolytic installations are made up of small units or cells, 
which may be combined in such a way as to produce any 
required amount of gas. Details of an electrolyzer cell are 
shown in Fig. 3. This type of cell is made by the Davis- 
Bournonville Co., Jersey City, N. J. The type illustrated 
provides current conducting areas and gas generating sur- 
faces amply proportioned to their requirements. There is suffi- 



16 GAS TORCH AND THERMIT WELDING 

cient over-capacity to minimize electrical resistance and afford 
high working efficiency. Long life of the vital parts is also 
insured. Research has shown that a nickel-iron-alkali com- 
bination of elements employed for electrolytic dissociation of 
water is a very efficient selection from an electrical input and 
gas producing standpoint. Parts subject to deteriorating action 
of any character are constructed of special material and pro- 
tected by processes especially adapted to service requirements. 
Care has been exercised in the design so as to avoid com- 
plication of electrical and mechanical connections of small 
cross-section. Thus studs, bolts, busbars and their contacts 
are amply large for all purposes. 

These eleetrolyzers are manufactured in two sizes, operating 
on specified currents of 500 and 1000 amp. respectively. The 
dimensions of the respective cells are 54 and 6I-2- in. high, 
13^ and 15J in. thick and 24^ and 36 in. wide. The licight 
given is from the bottom of tlie cell to the center of the highest 
horizontal tube, through which the hydrogen passes into the 
service pipe. 

In stating the production of gases evolved by dissociation 
of water the commonly accepted formula employed specifies 
production . of 7.93 cu.ft. of oxygen with double quantity of 
hydrogen per kilo-ampere-hours at normal temperature and 
pressure. The normal production of Davis-Bournonville elee- 
trolyzers may therefore, according to their booklet, be stated as 
follows : 

Noniiiil Hourly (Jlas rroduction 

Type Aiiiperagc Oxygen Hydrogen 

5 500 3.96 cu.ft. 7.92 cu.ft. 

6 1000 7.92 " 15.84 " 

at 20 deg. C. and 760 mm. barometer. 

The closed-cell type of construction adopted eliminates the 
absorption of carbon dioxide (CO2) by the solution exposed 
to the atmosphere in the open type of electrolyzer, and its 
consequent deteriorating effect upon the electrolyte and purity 
of gases. Electrical current passing tlu'ough the electrolyzer 
is converted almost entirely into chemical energy for producing 
oxygen and hydrogen. There being practically no action on 
the electrolyte employed as a conducting medium between 
the poles other than the dissociation of water, it is evident 



THE PRODUCTION OF WELDING GASES 



17 



that tlio electrical pressure or voltage required to send the 
specified amount of electrical energy through the apparatus 
is a measure of its efficiency. 

Referring now to the illustration, it should be kept in 




Fig. 3. — Details of the Davis Electrolyzer Cell. 



mind that the solution used is water with certain chemicals, 
such as sodium hydroxide (caustic soda) or potassium 
hydroxide (caustic potash), added to increase the conductivity. 
The reservoir in which the solution is placed, is divided by 



18 GAS TORCH AND THERMIT WELDING 

a metal plate A. Anodes B are suspended on each side of this 
plate, and on these the oxygen forms. The cell itself is made 
of metal, and the walls of this, as well as the sides of the 
metal plate A, form the cathode or negative pole from which 
the hydrogen gas rises. To keep the oxygen and hydrogen 
separated, asbestos sacks C are so placed as to surround each of 
the two anodes. The oxygen generated passes up through the 
hard rubber tubes D connected to the pipe E. The hydrogen 
passes up tube F into pipe G. The current to the anodes is 
conducted through the positive busbar assembly H. The nega- 
tive busbar assembly, shown at /, is attached to and forms 
part of the cast-iron cover of the cell and connects with the 
center plate and the tank walls. Valves for the three gas tubes 
are indicated by J. As the current passes through the cell 
the entire solution is charged and this results in the freeing of 
oxygen at the anodes and hydrogen at the cathodes. Since 
these gases have no tendency to pass off anywhere except at the 
respective terminals in the cell, the asbestos curtain effectively 
keeps them separated. The pressure of the two gases, how- 
ever, must be kept the same or the one having the higher 
pressure will be forced through the fabric of the asbestos sacks 
and mix with the other gas. This is taken care of by having 
the gases from the pipes E and G pass through a combined 
flash-back and pressure regulator. The function of this device 
is to receive the gases ; regulate their pressure through a simple 
water seal which equalizes the gas pressures inside the elec- 
trolyzer; separate and return to the cell any alkali carried 
over ; provide means of replacement of water to the cell ; bypass 
gases to the air if the delivery lines become obstructed, and to 
prevent admission of any flame to the electrolyzer. 

The replacement of distilled water, as needed, is made 
through the reservoir K, which combines the replacement func- 
tion with that of a hydraulic governor automatically adjusting 
the inner level of the solution. Under operating conditions, 
the usual replacement of distilled water amounts to approxi- 
mately one gallon per 100 cu.ft. of oxygen and 200 cu.ft. of 
hydrogen. This replacement and the ordinary inspection usually 
given to the electrical apparatus is practically all the atten- 
tion required for a battery of cells. 

The International Oxy-Hydrogen Generator. — The elec- 



THE PRODUCTION OF WELDiNG GASES 



19 



trolytic cell shown in Fig. 4 and in further detail in Fig. 5, 
is made by the International Oxygen Co., New York. Each 
cell unit requires a floor space 4 X 40 in., and with the neces- 




l^'iG. 4.— Cell Made by the International Oxygen Co. 

sary pipe connections, a head room of about 6 ft. These cells 
are intended to be run on a normal amperage of 600 and 
a voltage of 2.2 each, using a caustic soda solution. The 



20 



GAS TORCH AND THERMIT WELDING 



possible range above and below the normal amperage is con- 
siderable, without injury to the cells. An equipment of their 
type 4-1000 cells can be operated with good economy over a 
current range of less than 200 up to 1000 amp., representing 
a production range of more than one to five. In actual figures 
this means that an installation giving 600 cu.ft. of oxygen 



OXYGEN 

STANDARD 



CAS 
TRAPS 



WATER FEED 



HYDROGEN 



CXYG 
CAS 

CHAM 




Pig. 5. — Some Details of the Cell Construction. 



and 1200 cu.ft. of hydrogen per 24 hours, at 600 amp., can 
by varying the current and without any alteration in the 
plant, be made to deliver from less than 200 cu.ft. of oxygen 
and 400 cu.ft. of hydrogen, to more than 1000 cu.ft. of oxygen 
and 2000 cu.ft. of hydrogen per 24 hours. Operating at 200 
amp., the power consumption per unit of gas generated is 16 
per cent less than the normal 600-amp. operation. When 



THE PRODUCTION OF WELDING GA8ES 



21 



operating at 1000 amp., the power consumption per unit of 
gas is 15 per cent more than at 600 amp. 

Local rates will largely govern the number of cells required 
for a given output of the gases. Where the cost of current 




Fig. 6.— a Group of I. O. C. Cells. 

is low, the plant can be economically run on current above 
600 amp., the increased production per hour giving the re- 
quired amount with fewer cells, since the lower current cost 
justifies the slightly lower electrical efficiency. Where the 



22 



GAS TORCH AND THERMIT WELDING 



price of current is high, it will be advantageous to use current 
less than 600 amp., thus taking advantage of the higher elec- 
trical efficiency, but more cells will be needed. 

In general principles,, this make of cell resembles the one 




Fig. 7.— Suggested Layout of a 50-Cell Plant. 

previously described, though different in form. By referring 
to the illustration, it will be seen that a cell is made up of a 
tliin rectangular-shaped box frame to the sides of which are 
bolted two cast-iron plates or electrodes. The cavities formed 
between the center and side plates are divided by asbestos 



THE PRODUCTION OF WELDING GASES 



23 



fabric diaphragms, forming two chambers. The asbestos dia- 
phragms are clamped directly hy metal and are not held in 
place by either rubber or cement. In the upper part of the 




Fig. 8.— Suggested Layout of a 200-Cell Plant. 

east-iron frame are reservoirs for the electrolyte, from which 
it is fed to the two sides of the diaphragms. There are also 
two gas chambers at the top of the frame, which serve as gas 
traps and gas take-offs, as well as an automatic pressure- 



24 GAS TORCH AND THERMIT WELDING 

controlling dcvico. At the l)Ottom of the frame are com- 
municating passages which permit the equalization of densities 
in the electrolyte. Tlie cells are constructed of material which 
make them practically indestructible. Each cell is provided 
with an eye-bolt to facilitate handling. The electrodes are 
provided with a large number of pyramidal projections which 
greatly increase the area of contact with the electrolyte and 
facilitate the release of the gases at the generating surfaces. 
At 600 amp. the production of a plant per 24 hours is 105 
cu.ft. of oxygen and 210 cu.ft. of hydrogen per square foot of 
floor space. A group of cells is shown in Fig. 6. 

Two typical plant layouts are shofrn in Figs. 7 and 8. 
Fig. 7 is a layout for a 50-cell plant, with a normal capacity 
of 5760 cu.ft. of oxygen and twice as much hydrogen. This 
plant may be put in a corner of an existing building, and 
requires a space 22 X 24 ft. It is complete with all accessories 
except gas liolders and storage tanks. Fig. 8 is a separate 
plant of 200 cells, with all necessary accessories — such a plant 
as might be installed for public service in cylinders for gas 
users. Its main dimensions are 53 X 79 ft. and it has a normal 
capacity of 23,040 cu.ft. of oxygen and 46,080 cu.ft. of hydrogen 
per 24 hours. 

The Levin Type of Generator. — The generator made by the 
Electrolytic Oxy-Hydrogen Laboratories, Inc., Dayton, Ohio, 
and also of New York, is the design of I. H. Levin, after whom 
it is named. It is of the unit type, and is made up of a few 
standardized parts wdiich can be easily assembled. Details 
of one of the cells are shown in Fig. 9. From this it will be 
seen that in the main the general construction is the same 
as others on the market. One noticeable difference from those 
described, however, is that the electrodes are made independent 
of the casing, being separated from and securely fixed within 
the casing by specially designed blocks of asbestos. 

Each compartment has an independent water feed which 
also serves as a blow-off device to vent the gases under ab- 
normal conditions. The surfaces of both the anode and 
cathode are plated with cobalt, which is said to lower the 
over-voltage in excess of what the gas electrodes require. 
The cells are sent out entirely welded, and completely and 
rigidly assembled, so that they may be filled with electrolyte, 



THE PRODUCTION OF WELDING GASES 



25 



connected up, and put into service immediately. Each cell 
is 6\ in. thick, 25 in. wide and 30 in. high, and weighs 185 lb. 
AVith the ground supports, porcelain insulators and the piping 
system above, the total height is 4 ft. 8 in., which l)rings all 
the parts within the range of normal reach and vision. Even 







oxroEN offtake: pipe 

■ HTDROaFN OFFTAKE PIPE 



Minimum space fo be connected 
^'^n ^ rubber tubing 



W^i 



■ OXYGEN SIGHT FEED INDICATOR 
HYDROGEN SIOHT FEED INDICATOR 




INSULATOR., 
FRAME FOR ASBESTOS ---■ 



ASBESTOS DIAPHRAGM ■ 
CATHODE- 



ASBESTOS INSULATORS 



PORCELAIN INSULATORS 
' Floor Line 



Fig. 9. — Cross-Section of the Levin Generator Cell. 



a minimum aisle space of 30 in. will leave ample room for the 
removal or replacement of any cell. Each cell is intended 
to operate at a normal amperage of 250, requiring a little 
over Vio kw. per hour. A battery of 1000 cells will occupy 
a space 4J X 31 ft. and is claimed to produce 200 cu.ft. of 
oxygen and 400 cu.ft. of hydrogen per hour. 



CHAPTER III 

ACETYLENE AND MEDIUM, OR POSITIVE, PRESSURE 
GENERATORS 

Ac tyiene, which is the gas most commonly used witli 
oxygen for gas-torch welding, is produced by the reaction 
between calcium carbide and water. It is used because of its 
large carbon content and also because of its cndothermie 
properties, which means that it is heat absorbing and energy 
stored up in its formation is given off again upon dissociation. 
Calcium carbide and water produce acetylene and slacked lime, 
tlie formula being: CaC, + 2IL0 = CoHo + CaO(H„0). The 
calcium carbide when in contact with water is divided and 
the carbon of the carbide joins witli the hydrogen of the water 
to form acetylene gas. The calcium of the carbide unites with 
the oxygen of the water and forms slaked or hydrate of lime, 
as just stated. 

Since calcium carbide combines with water in all of its 
forms it must be protected from moisture in handling. For 
this reason it is shipped in sealed metal drums or cans com- 
monly holding 100 lb. From these drums the carbide is placed 
in generators for the purpose of liberating the gas. 

Like other gases used for welding or cutting purposes, 
acetylene may be purchased in cylinders, but it cannot be 
compressed directly into ordinary steel cylinders with safety. 
When compressed to as much as 30 lb. per sq.in., it becomes 
very unstable and liable to explode unless handled with ex- 
treme care. The heat generated by compression therefore 
makes this a dangerous process unless means are provided for 
cooling. The method used in order to compress the gas and 
make it safe to handle is to fill the cylinders with some porous 
substance and then fill them with acetone. Acetone is a liquid 
that has the property of absorbing acetylene about the way 
sugar does water, and acetylene in this state is commonly known 
as dissolved acetylene. As acetone takes up acetylene it in- 

26 



ACETYLENE AND MEDIUM PRESSURE GENERATORS 27 

creases in bulk. So suppose a cylinder to be filled only with 
acetone and dissolved acetylene under considerable pressure. 
If the cylinder gas valve is opened and some of the acetylene 
drawn off, the acetone will shrink in volume and leave a place 
in the cylinder filled with undissolved acetylene gas under 
pressure. This free acetylene under pressure is very explosive, 
and easily set off from shock or heat. However, it has been 
found that the gas will not dissociate when finely divided, and 
advantage is taken of this, and the cylinder or tank is filled 
with porous material. For this purpose a mixture of asbestos, 
charcoal, kieselguhr, and a small amount of cement to hold 
it together, is packed into the cylinder or tank, providing a 
finely divided porous filling that prevents dissociation of the 
gas. After a cylinder has been completely filled with this 
mixture, slightly dampened, it is baked in an oven until the 
moisture is completely driven off. It is then exhausted of air 
and acetone is introduced into the cylinder. Acetylene is then 
forced into this prepared cylinder, by means of a specially 
cooled, multiple-stage pump, great care being exercised during 
the process. Each cubic foot of acetone will absorb 24 cu.ft. of 
acetylene for each atmosphere (15 lb.) of pressure. However, 
in actual practice, the quantity of acetone in a cylinder is 
usually so regulated that the cylinder will contain about 10 
times its own volume of acetylene for each atmosphere of 
pressure that is on the gas. Cylinders are, as a rule, charged 
to 15 atmospheres pressure at 60 deg. F., so they contain 150 
times their own volume when charged. Thus a cylinder that 
would hold 2 cu.ft. of water when empty will hold 300 cu.ft. 
of acetylene at 225 lb. pressure, 60 deg. F. 

The filling material must be so placed in the cylinder as 
not to settle when handled or shipped, since if it does, a danger- 
ous pocket will be formed filled with free gas. In handling 
these cylinders, it should always be kept in mind that the 
pressure increases as the temperature is increased. The best 
results are obtained by keeping the cylinders of dissolved acety- 
lene at about 60 or 65 deg. F. An average cylinder of about 
100 cu.ft. capacity will weigh about 85 lb. and one of 300 cu.ft. 
capacity, about 220 lb. A Davis-Bournonville cylinder, 12 X 36 
in., 225 cu.ft. capacity, will weigh, fully charged, about 180 
pounds. 



28 GAS TORCH AND THERMIT \A ELDING 

Acetone Injurious to a Weld. — Acetone is very injurious 
to a weld, and in using gas from a cylinder of dissolved acety- 
lene, care must be exercised not to use the gas too fast or 
acetone will be drawn off with it. The allowable rate of cylinder 
discharge is at the rate of one-seventh of the capacity per hour. 
That is, a 225-cu.ft. cylinder will supply 225 ^ 7 = 32 cu.ft. 
per hour. Under emergency conditions this rate may be con- 
siderably exceeded, but the practice is not economical and is 
liable to injure the weld. 

The amount of gas in any cylinder may be found by noting 
the empty or tare weight stamped on the cylinder, then weigh- 
ing the cylinder and multiplying the difference in pounds by 
14^. In some cases the weight marking may be different, but 
in any case, each pound by weight of dissolved acetylene is 
calculated to produce 14^ cu.ft. of gas. To calculate the amount 
of acetylene used on any job, weigh the cylinder before and 
after and multiply the difference in pounds by the number 
just given. Knowing the cost of a cylinder of gas, the cost of 
the amount of gas used on any job may be easily found. 

Weighing, which has just been outlined, is the only ac- 
curate method of computing the amount of acetylene, since 
gage-pressure readings are affected by changes of temperature. 
However, gage pressures are a great convenience in estimating 
roughly how much gas remains in a cylinder. In the case of 
a 100-cu.ft. cylinder, each 15 lb. of pressure represents, ap- 
proximately, 6^ cu.ft. of gas, and in a 300-cu.ft. cylinder each 
15 lb. of pressure represents, approximately, 20 cu.ft. of gas. 

There are three types of acetylene generators, the essential 
differences being the method of bringing the carbide and water 
into contact. These three methods are : dropping the carbide 
into the water ; allowing the water to rise slowly into the 
carbide ; dropping the water onto the carbide. The first is by 
far the most satisfactory method and the one generally used 
in the United States, and for this reason will be the only method 
described. 

The carbide-to-water generators are of two types, known 
as positive- or medium-pressure, generators which deliver the 
acetylene at a pressure of more than 1 lb. and not to exceed 15 lb., 
and low-pressure generators which deliver gas at a pressure of 
less than 1 lb. While there are a number of firms making the 



ACETYLENE AND MEDIUM PRESSURE GENERATORS 29 

different types, only the better known makes will be described 
in detail, since the general principles arc the same. Modern 
generators of all types are automatic in their action, the feed 
being regulated by the flow of gas, and they are provided with 
an ample number of fool-proof device:; which render their opera- 
tion and handling safe. 

The Positive-Pressure Generator. — The first positive-pres- 
sure generator built was designed by Mr. Bournonville in 1906. 
The present type of pressure generator handled by the Davis- 
Bournonville Co., is made by the Davis Acetylene Co., Elkhart, 
Ind. These generators are made in several sizes to meet the 
demands of various sized shops, and they may be had in 25, 
50, 100, 200 and 300 lb. carbide capacity. These numbers in- 
dicate the weight of the charge of Calcium carbide to be used, 
the number of gallons of water per charge, and also the number 
cf allowable cubic feet of gas generated per hour in accordance 
with the rules of the National Board of Fire Underwriters. 

The generators of 50 lb. and 100 lb. capacity are standard 
for repair shops and light manufacturing, while the larger sizes 
provide for more 'extensive and continuous use in large repair 
shops and metal-working industries. They are of heavy con- 
struction with powerful feeding mechanism. They are fre- 
quently installed as units to build up plants for any require- 
ments of the oxy-acetylene process. They all have automatic 
feed with independent power and the quantity of carbide re- 
maining in the hopper is constantly indicated. The acetylene 
gas is piped directly from the generator under the required 
pressure through service pipe lines to the welding stations and 
is regulated by means of reducing valves fitted with pressure 
gages to govern the proper working pressure. 

The size of carbide used in the Davis stationary generators, is 
designated as 1^ X f in., and it is estimated to produce ap- 
proximately 4^ eu.ft. of acetylene gas to a pound of carbide. 
The size of carbide just quoted has reference to the size of 
screen mesh it will go through or not, that is : 1^ by f in, means 
that the lumps will all go through a 1-|- in. mesh screen, but 
none through a f -in. mesh ; carbide quoted as ^ by jV in. size, 
will go through a ^-m. mesh screen, but not through a jV-in. 
mesh, and so on. This smaller size is estimated to yield about 
4 eu.ft. of gas per pound of carbide. 



30 



GAS TORCH AND THERMIT WELDING 



The carbide-to-water generators are designed to hold a gallon 
of water for each pound of carbide capacity. In practice the 
carbide is fed into the water only in sufficient quantity to 
maintain the gas supply at the required pressure. The extreme 
limit of safety pressure for free acetylene is 30 lb. and in the 




Fig. 10. — Stationary Type of Positive-Pressure Acetylene Generator. 



positive-pressure types of generators the pressure limit is placed 
at 15 lb. When this pressure is reached, the various safety 
devices begin to act to prevent further generation and conse- 
quent increase in pressure. As the carbide is fed from the 
containing hopper it drops down into the tank of water beneath, 



ACETYLENE AND MEDIUM PRESSURE GENERATORS 31 




FeeJing 

Diaphragm 



ffo/e 
-rp/pe 
nnsac/ 



I Pipe Tap-. 

Fig. 11. — Details of 300 Lb. Carbide Capacity Acetylene Generator. 



32 GAS TORCH AND THERMIT WELDING 

and sinks to the bottom. In this way most of the gas is gen- 
erated close to the bottom of the water tank, and has to rise 
through a considerable body of water to reach the top. This 
not only serves to cool the gas but also washes out a large part 
of the impurities. The carbide used in these generators may 
be obtained from distributing points in nearly all of the large 
cities in the country, in sealed drums containing 100 pounds. 

The acetylene generator shown in Fig. 10 is the Davis 
standard stationary 300 lb. carbide capacity apparatus. It is 
115 in. high, 42 in. in diameter, and weighs about 1000 lb. 
Details of this apparatus are shown in Fig. 11. In this cut, 
A is the hopper into which the carbide is introduced from the 
top. A feeding mechanism at the bottom of this hopper is 
run by the clock motor B, which is operated by means of the 
weight C. The feeding device consists principally of a rotating 
disk with inclined vanes which sweep the lumps of carbide off 
into the water below. There are two safety-pressure diaphragms 
for stopping the motor should the gas pressure become too 
high. The first diaphragm acts when the pressure reaches 15 
lb. If this should fail to act properly, the second diaphragm 
will be actuated a little above 15 lb. pressure. This last dia- 
phragm operates a positive lock which effectually stops th-e 
motor and consequently the carbide feed. In addition to this, 
there is a safety valve at E which is connected to a pipe leading 
to the outside of the building, so that the gas can escape in 
safety. At I> is a funnel by which water is run into the tank. 
As the gas is generated it is carried through the pipe F to the 
bottom of the flash-back chamber G. This chamber is full of 
water and serves the double purpose of giving the gas a second 
vrashing, and acting as a water seal between the service pipe 
and the gas in the generator. From this chamber the gas passes 
up through the filter chamber H, which is filled with asbestos 
that removes suspended impurities. From this filter the gas 
passes out through valve / into the service pipe and thence to 
the torches. The handle J operates the agitator and the tank 
settlings are removed through the gate valve K. 

In addition to the regular stationary type, the Davis-Bournon- 
ville Co. makes what is called a "Navy Type." These comprise 
a complete equipment for use in ship-building yards, railway 
systems, and large industries. The installations provide acetylene 



ACETYLENE AND MEDIUM PRESSURE GENERATORS 33 



SSHgSBSeWSKiWMSKHfflS^SSSiW^^ , ' 




Ph 



O 



34 



GAS TORCH AND THERMIT WELDING 




ACETYLENE AND MEDIUM PRESSURE GENERATORS 35 

generation with two-pressure, air-excluding generators of large 
capacity , supplying acetylene under direct pressure to welding 
and cutting stations and an additional low-pressure supply for 
compression into portable safety cylinders, with purification sys- 




FlG. 14. — All-Steel Hand Truck for Holding Gas Cylinders and 
Welding Outfit. 

tern, and three-stage specially designed acetylene compressor. 
Three sizes of the navy type, two pressure, air-excluding acety- 
lene generators are manufactured, having a capacity of 100 lb., 
200 lb., and 300 lb. of carbide each, and with normal output of 



36 GAS TORCH AND THERMIT WELDING 

100, 200 and 300 eu.ft. of acetylene per hour respectively. 
When greater capacity than 300 cu.ft. of acetylene per hour 
is desired, two or more generators may be connected serially with 
a special purifying and compressing plant. 

A navy type installation is shown in Fig. 12 and a suggested 
plant layout in Fig. 13. One of the special features of the 
navy installation is the low-pressure supply from which the 
gas is drawn for charging portable cylinders. This is done 
because in many places around a shipyard or other large plants, 
it would be practically impossible to pipe the gas or to use a 
portable generator. The cylinders used are, of course, previously 
prepared as already outlined. After charging they may be 
transported to the work in various ways, but for convenience 
they may be mounted on a small hand truck, like the one shown 
in Fig. 14. This truck holds an acetylene cylinder and an oxygen 
cylinder, together with the necessary accessories. 

The approximate dimensions and weights of the various 
types of generators made by the Davis-Bournonville Co. are 
given in Table T. 

The Buckeye Carbide-Feeding Mechanism. — The phantom 
view given in Fig. 15 illustrates the feeding mechanism used 
by the Macleod Co., Cincinnati, Ohio, on their pressure gen- 
erators. These are made on the same principle as those just 
described, but this illustration gives a clearer idea of the ar- 
rangement of the feeding device. The operating motor is driven 
by a weight which is wound up by means of the handle on top. 
The way the vanes are set so as to sweep the carbide lumps 
into the hole in the center of the bottom of the hopper, is clearly 
shown. 

Since commercial demands frequently make a portable type 
of acetylene pressure-generating apparatus desirable, such ap- 
paratus particularly suited to the requirements of large shops, 
ship or railroad yards and the like, is made by several firms. The 
Davis Acetylene Co. makes them in two sizes, of 25- and 50-lb. 
capacity. These generators are provided with a locking mechan- 
ism which prevents the operation of the feeding mechanism 
when the generator is being moved. 

The Portable Pressure Type. — The portable pressure type 
of generator made by the Oxweld Acetylene Co., Newark, N. J., 
and Chicago, 111., is shown in Fig. 16. These generators are 



ACETYLENE AND MEDIUM PRESSURE GENERATORS 37 





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38 



GAS TORCH AND THERMIT WELDING 



made with 50- and 100-lb. carbide capacity and respective pro- 
ductions of 50 and 100 cu.ft. of acetylene, capable of supplying 
3 and 6 torches. The 50-lb. generator is 3 ft. 1 in. wide, 3 ft. 
3 in. long and 5 ft. 8^ in. high. It is mounted on a 4-whceled 
truck 4 ft. 5 in. wide and 7 ft. 8 in. long, with an over-all 
height of 6 ft. 11^ in., and a weight of 1750 lb. The 100-lb. 




Fig. 15.- — The Buckeye Carbide-Feeding Mechanism, 

size is mounted on a truck 9 ft. 5 in. long, 4 ft. 10 in. wide, 
has an over-all height of 8 ft. 6 in., and weighs 2300 lb. This 
type of generator consists of a single shell which contains both 
the carbide hopper and the generating tank. There is no 
gasometer, the carbide-feeding mechanism being controlled by 
the pressure of the generated gas against a flexible diaphragm. 



ACETYLENE AND MEDIUM PRESSURE GENERATORS 39 

The feeding mechanism is positive in action and is provided 
with an automatic auxiliary no-pressure stop mechanism which 
closes the feed opening in case the pressure in the generator 
should be reduced to zero through a leak in the line or con- 
nections or by reason of any derangement in the controlling 
device. A locking handwheel positively locks the feed mechan- 
ism in its closed position when the generator is out of service 




Fig. 16. — Oxweld Portable Pressure Generator. 



or when it is desired to move it from place to place. This 
effectually prevents any carbide from falling into the water 
or the water from splashing onto the carbide while the generator 
is being moved. A complete system of interference devices 
connecting the filler cap, feed mechanism and residuum gate 
provides against mistakes in operation. The hydraulic back- 
pressure valve is of heavy construction and is provided with a 



40 



GAS TORCH AND THERMIT WELDING 



pop valve of ample size to carry off any excess pressure. The 
generator is also provided with a diaphragm relief valve of 
special design. The filter has a cover which is interlocked with 
the shut-off cock to prevent the escape of gas when the lid has 
been removed for cleaning purposes. 

The construction of the generator throughout is of a heavy 
and substantial- character. It may be mounted on a 4-wheel 
truck, as shown in the engraving, or it may be located in a 
stationary position. Space is provided on the truck for three 
oxygen cjdinders and a tool chest, making the entire equipment 
self-contained. 

This same concern also makes other pressure generators in 
200-, 300- and GOO-lb. capacities. 



Height, 
Acetylene Generators Inches 

100 \h. carbide capacity 78 

200 11). carbide capacity 104 

300 lb. carbide capacity 115 

Gasometer, 100 cu.t't. capacity 120 

Height, 
Inches 

Driers, each -40 

Oil separator •''>2 

Purifier, 24 x 36 X '^^ inches 

Compressor, 31 X 36 X '^^ inches 



Diameter, 


Weight, 


Inches 


Lb. 


30 


800 


36 


1000 


42 


1200 


76 


1500 


Diameter, 


Weight. 


Inches 


Lb. 


16 


80 


6 


200 




800 




2500 



CHAPTER IV 

LOW-PRESSURE ACETYLENE AND THERMALENE 
GENERATORS 

The use of a low-pressure acetylene generator, the pressure 
of which is limited to 1 lb. or less, makes it possible to use a 
gasometer for the storage of the generated gas, with its accom- 
panying advantage of absolute volumetric or pressure control. 
A phantom view of a typical low-pressure generator, made 
by the Oxweld Acetylene Co., is shown in Fig. 17. The 
carbide-feeding mechanism and tank closely resemble that of 
the pressure type, and with the exception of the gasometer 
and its mechanism, the rest of the apparatus resemble it also. 

The possibility of loss of gas through ordinary leakage in 
the line and connections is practically eliminated with the low- 
pressure system. The gas bell A provides storage for gas and 
effectively guards against the loss due to after-generation. 
Control of the carbide-feed mechanism is accomplished through 
the rise and fall of the gas bell, giving a very constant gas 
pressure. The movement of the gas bell gives a dual motor 
control, first through a carefully adjusted friction brake, which 
provides for gradual starting and stopping, and, second, through 
a positive jaw clutch. Special provision is made for shutting 
off the motor feed when the gas bell is in its lowest position, 
which might result from a severe leak in the line or connections. 

Operation of the generator is effected by a small but efficient 
weight-driven motor B, which is automatically started and 
stopped in proportion to the amount of gas being used. The 
motor weights C always lower approximately the same distance 
for each pound of carbide used, and constitute a reliable in- 
dication of the amount of carbide remaining in the machine at 
any time. The generator requires no attention whatever other 
than periodic recharging with carbide and water. By the use 
of a positive forced feed, it is impossible for more than the 

41 



42 



GAS TORCH AND THERMIT WELDING 



proper quantity of carbide to be fed to the water at a time. 
In order to secure cool, and hence efficient, generation, it is 
necessary to have not less than one gallon of water capacity per 
pound of carbide charge. This requirement is met by all of 
these generators. 

A complete and efficient system of interlocking safety de- 



yr FILTER 




HYDRAUUC 
BACK-PRESSURE 
VALVE 



Fig. 17. — Sectional View of Oxvveld Low-Pressure Generator Showing 
Interior Arrangement and Direction of Flow of Gas. 



vices prevents mistakes in operation due to carelessness or for- 
getfulness when charging the generator. The hydraulic back- 
pressure valve Avith three distinct water seals prevents the pos- 
sibility of any oxygen entering the generator. 

The generator is equipped with an agitator D, which churns 
the residuum thoroughly, allowing it to flow out freely and 



LOW-PRESSURE ACETYLENE GENERATORS 



43 



quickly when the residuum outlet is opened for recharging. 
These low-pressure generators use the nut, or 1:^- X §-iii. size 
carbide. 

The Oxweld Duplex Generators. — The duplex form of gen- 
erator, shown in Fig. 18, is designed to meet the requirements 
of many industries, where continuous operation of the generator, 
without interruption for cleaning or repairing, is essential. It 
is made up of two of the low-pressure generators, both deliver- 




FlG. 18. — Oxweld Low-Pressure Acetylene Generator, Duplex Type. 

ing to the same gasometer. Either generator can be operated 
independent of the other, allowing one to be used while the 
other is being recharged. The low-pressure generators are made 
in a number of sizes, details of which are given in Table II. 

Eeputable manufacturers always supply detailed instructions 
as to the care and maintenance of their generators. These 
should be posted in a permanent place near the generator and 
should be strictly adhered to in setting up, starting, and 
refilling. 



44 



GAS TORCH AND THERMIT WELDING 



The following general prccantions should always be ob- 
served : 

In charging a generator never use anything but the hands 
or a wooden stick to poke the carbide, on account of the danger 
of causing a spark. 

Table II. — Oxweld Low-I*ressure Gkneratoe Sizes 



Carbide 
Capacity 


Single or 


Gas 

Capacity 
Cu Ft 


Approx. 
No. of 


DIMENSIONS 


Approx. 
Shipping 
Weight, 


Min. 
Width 
of Door 


in 


Duplex 


Per 


Blow- 








Com- 


Through 


Pounds 




Hour 


pipes 


Height 


Length 


Width 


plete 
Plant 


Which 

Gen. will 

Pass 


SO 


Single , 


50 


3 


7' 4" 


5' 7" 


3' 2" 


1400 


29y," 


50 


Duplex 


50 


3 


7' 4" 


8' 10" 


3' 2" 


1800 


29'A" 


100 


Single 


100 


6 


7' 6" 


6' 2" 


3' 7" 


1900 


33" 


100 


Duplex 


100 


6 


7'b" 


9' 8" 


3' 7" 


2400 


33' 


200 


Single 


200 


12 


9' 4" 


8' 0" 


5'0" 


2500 


41" 


200 


Duplex .. . 


200 


12 


9' 4" 


13' 0" 


5'0" 


3500 


41" 


300 


Single 


300 


18 


10' 1" 


>8' 10" 


S'V 


4100 


48" 


500 


Duplex 


300 


18 


10' I" 


14' 1" 


5' 4" 


4800 


48" 


500 


Single, ,.,., . 


500 


!0 


ir7" 


11' 3" 


6' 6" 


4800 


62" 


500 


Duplex .. . 


500 


30 


ir 7" 


18' 0" 


6' 6" 


6500 


62" 



As far as practicable do all charging, cleaning, adjusting, 
and manipulating of the generator by daylight. 

Avoid as far as possible the introducing of air into the 
generator, or the circulation of air through it. Never leave any 
opening in the machine open longer than is necessary and never 
have any two openings, such as the carbide charging door and 
the sludge valve, open at the same time. 

Keep the generator full of water at all times, even when 
not in use. AVhen the sludge is drawn off and the machine 
flushed out, do not do anything else until it has been refilled 
as directed in the instructions for recharging it. 

Never open the carbide filling plug, charge the machine with 
carbide, do any adjusting or manipulating, or make repairs, 
unless the generating chamber is full of water, as directed in 
the instructions for operating the generator. 

Renew the water in the generating chamber each time any 
carbide is placed in the hopper. Never run more than one 
charge of carbide into the generating chamber without refilling 
with fresh water. Do not experiment. 

If water in any chamber of the generator should freeze, do 
not attempt to thaw it with anything but hot water; and then 
examine the generator carefully for any damage which freezing 
may have caused. 



LOW-PRESSURE ACETYLENE GENERATORS 45 

If the generator should ever require repair: First, remove, 
all carbide ; second, drain all water from the generating 
chamber, then refill the generating chamber as if for recharg- 
ing; third, disconnect the generator from piping and remove 
it to the open air, then fill all the compartments with water 
and thus force out all mixtures of gas and air before applying 
soldering irons or any tools that could cause a spark. See that 
the workmen removing or repairing the generator understand 
this thoroughly. 

Familiarize yourself thoroughly with the directions for 
operating your generator, which are furnished liy its makers ; 
and when recharging the machine follow them in the order in 
which they are given. 

Thermalene Generators. — In composition and method of pro- 
duction, thermalene differs from any gas previously used for 
welding purposes. It is a combination produced by the de- 
composition of calcium carbide and hydrocarbon oil, the heat 
generated by the carbide being used to vaporize the oil. It is 
the discovery of Karl Friedrich Linus Wolf, of Zurich, Switzer- 
land, and is handled in this country by the Thermalene Co., 
Chicago Heights, 111. 

Thermalene generation is a very unique proposition and 
was first fully described in the "American Machinist," Aug. 
10, 1916. At present thermalene is principally used for welding 
or cutting metals, in which it is used together with the proper 
mixture of oxygen. The nature of the gas will be better un- 
derstood by first giving a description of the method by which 
it is produced. 

A phantom view of a generator is shown in Fig. 19. To 
prepare this generator for operation, water is poured in through 
funnel A until it will run out of pet-cock B, which fills the 
easing about two-thirds full. The generating mixture is carried 
in a tin can or cartridge that is inserted from the bottom into 
the cartridge chamber, as shown at C. Previous to inserting 
the cartridge, however, care is taken to pull down the cam lever 
D, which pulls up the rod and closes the water valve E. This 
prevents any water entering the cartridge chamber. After the 
cartridge has been inserted through the door in the bottom of 
the chamber, the door is closed and the bar F brought up and 
locked by means of the handwheel G. To generate gas the cam 



46 GAS TORCH AND THERMIT WELDING 

lever on top is pulled up as far as it will go. This admits 
water from the water chamber H into the cartridge chamber 
through the center tube to the bottom of the cartridge, from 
where it begins to work upward. 

How the Cartridge Is Packed. — The cartridge is packed with 



Tig. 19. — Phantom View of Thernialene Generator. 

alternate layers of calcium carbide and crude oil mixed with 
sawdust. The water as it rises slacks the carbide and generates 
acetylene gas. The heat caused by the slacking of the carbide 
layer vaporizes the oil in the layer of mixed oil and sawdust 
immediately above the layer of slacking carbide and generates 



LOW-PRESSURE ACETYLENE GENERATORS 47 

oil-gas. When the gas pressure as indicated hy the gage is up 
to 5 Ih., the valve J is opened, which lets the gas enter the 
hose leading to the storage tank or torch. The pet-cock at K 
is used to drain off the impurities, such as phosphor-hydrogen 
or ammonia, which have been separated from the carbide gas 
in the process of generation. At L is a check valve, which allows 
gas to escape from the cartridge chamber, but effectually pre- 
vents any return of either gas or water. As soon as a cartridge 
is exhausted it is easily removed, carrying all of the dirt and 
sludge with it. 

With the use of a storage tank, enough gas is carried to run 
a torch while a new cartridge is being put in place in the 
generator, if needed. The pressure limit for welding or cutting 
is 15 lb. When this pressure is reached, a regulating diaphragm 
at M automatically cuts off the water feed and stops the genera- 
tion of gas. This diaphragm is placed at the top of the generator, 
on the inside, where the gas pressure acts directly on it. The 
diaphragm is connected to the feed-valve rod in the center, so 
that as the diaphragm is forced upward by the gas pressure, 
the water valve is partly or wholly closed. It is so arranged 
as to be easily set for various desired pressures. 

As previously stated, the cartridges are made up of alternate 
layers of calcium carbide and oil-soaked sawdust. Now it is 
well known that the volume of lime into which calcium carbide 
is converted by the slacking process is greater than the volume 
of the carbide. Therefore, when carbide is packed tightly in 
cartridges, as desirable, the expansion is liable to burst the 
case, and in some instances might cause the cartridge to jam 
in the chamber, as well as interfere with the successful working. 
One of the objects then is to so make the cartridge as to allow for 
the expansion of the contents. Another is to prevent the oil 
from coming in contact with the carbide, as this would interfere 
with the action and decrease the gas output. To summarize, 
the cartridge components must be so arranged as to promote 
free action of the carbide; free action of the heat evolved from 
the carbide on the volatile substance ; to prevent action of 
moisture on the carbide layers not being acted upon purposely ; 
and to promote the free discharge of the generated and volatilized 
gases. 

All of these points, as well as a number of others, have 



48 



(!AS TORCH AND THERMIT WELDING 



been considered in the makeup of the cartridges, as shown in 
detail in Fig. 20. As made at present for commercial purposes, 
there are four sizes corresponding to the different outfits. The 
cartridges consist of a tin can of suital)le size, the smallest 
being 4^g in. in diameter and 8 in. high, weighing 6 lb. and 
having a gas-producing capacity of 25 cu.ft., sufficient to supply 
a welding torch from four to five hours. The largest size is 
92- in. in diameter and 16 in. high, weighing 40 lb. This has 




Carbide 



'Spacer 



Sandvsf covered 
wfih Cloih 



■Screen 




■k: c 

Fig. 20. — Details of Thernialene Cartridge. 

a gas production of 200 cu.ft., or eight times the capacity of 
the smallest size w^hich has been previously mentioned. 

Referring now to the illustration, a cylindrical screen A is 
first placed in the can to be filled and then a layer of carbide 
is placed in the bottom of the can around the screen tube. An 
unglazed carboard disk B is next placed on top of the carbide. 
A spacer T', made of thin metal bent so as to lie edgewise, is 
placed on top of the cardboard and then a disk of screen is put 
over it. Sawdust impregnated with crude oil in a cloth sack 
made of two cloth disks sewed together is laid on the screen. 



LOW-PRESSURE ACETYLENE GENERATORS 49 

On this is another screen, then a spacer and a cardboard disk, 
and so on to the top, ending with a sack of oil, soaked sawdust 
covered with a piece of screen that has no hole in the center 
for the cylindrical tube. The end of the can is closed with a 
cover for handling, which is removed before placing in a 
generator. 

As previously mentioned, the water feeding in through the 
valve in the cartridge chamber drips down through the cyjin- 
drical screen tube and starts slacking of the lower layer of 
carbide, the heat of which vaporizes the oil in the sack above 
it. The cardboard disks, while strong enough to hold the layers 
firmly in place while dry, begin to soak up as soon as the 
feeding starts, and consequently become soft, so as to give way 
under the pressure of the expanding carbide, allowing it to be 
forced into the spacing between the carbide and the oily saw- 
dust. This space is so calculated as to keep the various layers 
firmly in place until the cartridge is exhausted. Another thing 
is that, as any liberated steam or water vapor must pass through 
the absorbent cardboard as well as the oil, before it reaches the 
next layer of carbide, action of the steam on the carbide above 
is prevented. This insures that the respective layers of carbide 
will not be acted upon until the water becomes level with them 
in turn. In consequence, a cartridge can remain in a generator 
a long time without becoming spent. The screen disks on top 
and bottom of each layer of oily sawdust furnish efficient 
volatilization and egress for the gas. 

By the method of producing thermalene, the heat evolved 
by the generation of acetylene is absorbed, at the place of 
generation, in the production of the oil gas. This utilization 
of heat serves to keep the temperature down, since the heat 
generated is used and dissipated by the latent heat of the oil, 
so that radiation and absorption by water is not necessarily 
depended upon. The gas combination that results passes out 
through the T-pipe ends and bubbles up through the water into 
the upper part of the generator. The low temperature causes 
the impurities to drain back into the chamber, from which they 
are easily removed. The layers of carbide and oily sawdust 
are so proportioned as to cause only the vaporization of the 
lighter oils, such as benzine, naphthalene, kerosene and the like. 
The temperature is not high enough to vaporize the tar oils, 



50 GAS TORCH AND THERMIT WELDING 

as these cue Iieuvy and give a deposit of lampblack. These 
heavy oils are therefore not utilized, but remain in the cartridge. 
The temperature in the cartridge is maintained between 200 
and 300 deg. C. (392 to 572 deg. F.), depending upon the 
rapidity with which the gas is being used and the amount which 
is generated and delivered. It is not intended that an actual 
boiling take place at any time, for if the temperature is too 
high there will be a vaporization of the heavy oils, causing de- 
posits in the pipes and also an increase in the impurities. The 
gases passing through the pipes cooled by the water of the 
generator are kept between 60 and 70 dog. F. In the passage 
through the cooled pipes the impurities are removed in the 
following manner : Acetylene has a comparatively high specific 
heat, so that its rate of cooling when passing through the pipes 
is low. The specific heat of oil gas is, however, only one-eighth 
of that of acetylene, so that its cooling effect will be eight times 
as great. Now if the two gases are passed together along a 
cooling surface, the temperature of low specific heat will de- 
crease rapidly and cause a rapid lowering of the temperature 
of the other gas. This causes a deposit of the vapors suspended 
therein. So this action results in the deposit of the sulphur, 
j)hosphorus and silicon compounds, and of the ammonia. In 
order, however to bring about this precipitation the temperature 
must be sufficiently low — that is, as stated above, between 60 
and 70 deg. F. If the gas finally issuing from the pipes and 
water was too hot, the impurities would not be thrown out. 

In this process the acetylene and oil gas, generated and 
cooled, will combine in the pipes after the impurities are re- 
moved. It is important, however, that the impurities be removed 
and the product sufficiently cooled, since no real combination 
will take place at too high a temperature. For instance, if the 
water is above 180 deg. F. the oil burns and no proper com- 
bination results. 

The combined gas produced, named thermalene, possesses 
marked characteristics that distinguish it from oil-gas, from 
acetylene, and from the usual mixture of the two. The density 
is greater than air, being 1.1 taking air as unity. The issuing 
gas can be seen to sink when thrown through a sunbeam. The 
specific heat is low, being a little over one-eighth of that of 
acetylene. Thermalene liquefies at between 1400- and 1500-lb, 



LOW-PRESSURE ACETYLENE GENERATORS 



51 



pressure per square inch at room temperature, and in its liquid 
state is nonexplosive and stable. A very noticeable thing is the 
odor, which is not at all like the odor of either acetylene or 
of oil-gas, but is a soft, sweet smell, not strong or offensive in 
any way. The color is white, but with a predominating pro- 
oortion of the red and yellow parts of the spectrum. The 




Fig. 21. — Thermalene Outfit for Shop Use. 



maximum flame temperature, according to H. McCormack, pro- 
fessor of chemical engineering. Armour Institute of Technology, 
Chicago, 111., has been found to be about 6500 deg. F. The high 
density of the gas has a number of advantages. It has more 
body than acetylene and does not need so much oxygen. More- 
over, it mixes better with oxygen. It does not explode as 



52 



GAS TORCH AND THERMIT WELDING 



readily as acetylene, so can be mixed with greater proportions 
of air. In a Bunsen burner it is possible to mix as much as 
32 per cent of air without causing a flareback. It can readily 
be turned down without causing a flareback, and it can be used 
with a Welsbach mantle to advantage. The upper and lower 
explosive limits are 12 per cent and 30 per cent. It averages 
approximately 13.97 cu.ft. per pound. 

Some Advantages of Thermalene. — When used for welding 
and cutting, thermalene has numerous good points. It does not 




Fig. 2:i. — Portable Thermalene Generator Outfit. 



require an excess of oxygen, and the flame, therefore, produces 
a soft weld, especially in cast iron. When welding it is notice- 
able that less sparks are thrown ofl than when using acetylene. 
It can be used at a lower pressure also, owing to its greater 
calorific value. Owing to the removal of the various impurities, 
there are no corrosive effects on fittings, nor poisonous effects. 
It is also for this reason that there is little or no danger of 
explosion. Neither does the spent cartridge give off explosive 
gases, for the reason that the gases liable to cause explosion are 
separated and drained off from the generator chamber. Cor- 



LOW-PRESSURE ACETYLENE GENERATORS 53 

rosion of interior walls, due to water action, is prevented by the 
oil vapor which is always present and forms a protecting and 
scaling effect throughout. 

A thermalene generator may discharge its gas into a storage 
tank, or the gas may be used direct from generator to torch. A 
welding or cutting outfit, suitable for shop use, where it will 
not need to be moved frequently, is shown in Fig. 21. Here 
the gas is used direct from generator to torch. The smallest 
generator like the one shown is 10^ in. in diameter, stands 3 ft. 
9 in. high, and weighs about 60 lb. An apparatus mounted on 
a truck is shown in Fig. 22. As a rule a No. 2 generator is 
used for this purpose. This size is 16 in. in diameter, stands 
6 ft. high, and will produce 70 cu.ft. of gas with one charge, 
the generator weighing 225 lb. and the storage tank 120 lb. 
The largest size generators will produce 200 cu.ft. of gas per 
charge, and they may be coupled in batteries where a large 
amount of gas is desired. These can be arranged so that part 
of them can be recharged while the others are working, or 
storage tanks of sufficient capacity may be used to allow for 
recharging. 



CHAPTER V 
GAS TORCHES USED FOR WELDING 

The gas torches used for welding in the United States may 
be divided into two general types, known as medium-pressure 
and low-pressure torches. Each type is made in a number of 
sizes, and each size is usually provided Avith a number of in- 
terchangeable tips for producing flames of different size. 

The medium pressure torches arc also known as positive- 
pressure torches, and to avoid misunderstanding, they will be 
referred to as positive-pressure torches hereafter. In these 
torches, using acetylene and oxygen for welding, the acetylene 
pressure will range from 1 to 14 lb. and the oxygen pressure 
from 1 to 24 lb. per square inch, the pressure employed de- 
pending on the thickness of the metal being Avoided, the make of 
torch, and the tips used. The pressures given may even be 
exceeded in some exceptional cases. 

A sectional view of a typical positive-pressure welding head 
is shown in Fig. 23. The oxygen enters at A and the acetylene 
enters at B. The oxygen goes to the small chamber C and 
thence out through the center hole. The acetylene goes to the 
chamber D and also out through the center hole, the two gases 
starting to mix at the point E, and as they pass out through 
the channel F to the end of the tip, they are thoroughly mixed. 
In this illustration, the removable tip is indicated by G. This 
m.ake of tip has a conical seat and held in its place by means 
of the lock collar H. Made in this way, there are no threads 
on the tip itself, although the practice varies in different makes. 

The low-pressure torch is also known as the injector type. 
In this type of torch, the acetylene, or other gas, is supplied 
under a pressure of a few ounces up to 1 lb., but the oxygen 
may have a pressure of from 5 to 30 lb. per sciuare inch, accord- 
ing to the size of tip being used. In some cases the oxygen 
pressure may be either higher or lower than the figures given. 

54 



GAS TORCHES USED FOR WELDING 



55 



A sectional view of a typical low-pressure torch is shown in 
Fig. 24. In this torch the acetylene, or other gas, enters at A 
and the oxygen at B. The acetylene goes to the chamber C 
from which it is sucked by the oxygen pouring out through 
the nozzle at D, and it is carried along with the oxygen into 
the mixing chamber E in the tip of the torch. From this 
chamber the gases issue thoroughly mixed and ready for com- 
bustion. 

As they qualify for classification as either positive-pressure 




Figs. 23 and 24. — A Typical Positive-Pressure Welding Torch and a Low- 
Pressure or Injector Type of Welding Torch. 



or low-pressure types of torches, the various makes of each type 
differ principally in form, the general principles of action 
remaining the same. A few examples of the different makes 
of positive-pressure torches will be shown first, and these will 
be followed by others of the low-pressure or injector type. 

A standard form of a positive-pressure welding torch, made 
by the Davis-Bournonville Co., is shown in Fig. 25 and in detail 
in Fig. 26. A number of torches used for various purposes are 
shown in Fig. 27. In this illustration, A is a small lead-burning 
torch. B is a midget torch used for welding very light sheet 



56 



GAS TORCH AND THERMIT WELDING 



metal for manufacturing purposes, sucli us the seams of cooking 
utensils, aluminum ware, etc. It weighs about 8 oz., is 10 in. 
long, and may be used on sheets up to ^ in. thick. C is a small- 
size torch for metal from V32 to Vie ii^- tliick, weighs 18 oz., is 
14 in. long and uses oxygen pressures, with different tips, of 




Fig. 25. — The Davis-Bournonville Style C Positive-Pressure Weldiug Torch. 



Carburetinq device which posH-ivelycino/ 
[infimai-eiy mixes the iwo gases in proper proportion 

_ . ^-. .OXYGEN ■ 

Conical \ jiMii nil f— t- 

Orounc^ i^^ ' 

Seaf"-^ 



Ox/(^en neec^/e 
Valve \ 




'ACETYLENE 



'^The two gases strike 
together at right angles 
creating a vortex which 
insures intimate mixture 



Acetylene neeolle 
Valve 




The oliameters of the parts in the carbureting alevice 
are proportionect to each size of tip, to deliver proper 
volumes of gas for each size of flame proaucec^. 

^"Luminous Cone of flaime 

Secondary reaction. Hydrogen and carban 
monoxide burn, fa/<ing the necessary oxygeri 
from the air and produce ^vater vapor and 
carbon dioxJde. 



ilJlll'. 



'ir ill 



Fig. 26 Details of the Davis-BournoBville Welding Torch. 



from 2 to 10 lb. D is a manufacturer's torch, intended for 
use on boilers, steel barrels, metallic caskets, tanks, cylinders, 
etc. The head is set at right angles to the body, which has been 
found best for this work. It weighs 24 oz., is 18 in. long and 
uses oxygen at 2 to 10 lb. pressure, according to the tips em- 
ployed. E \h a large torch for heavy welding. It weighs 2 lb., 



GAS TORCHES USED FOR WELDING 



57 



is 20 in. long, and uses oxygen at 12 to 20 lb. pressure. It is 
used on metal from | in. thick up. F is a, water-cooled torch, 
used for heavy welding where the tips have a tendency to be- 
come overheated. It is 36 in. long and weighs about 3^ lb. 
Four lines of hose are needed with it, two for water and two 

A 





Fig. 27. — Various Models of Davis-Bournonville Welding Torches. 

for gas. G is used for welding with oxygen and hydrogen. H 
is for use on a welding machine. / is a water-cooled torch for a 
welding machine. J is water-cooled, for machine use and has 
a multiple-jet nozzle or tip. All of the torches mentioned are 
furnished with five interchangeable tips for different thick- 



58 



GAS TORCH AND THERMIT WELDING 



nesses of metal. These tips, however, do not fit torches of 
different size; that is, the tips for large torches will not fit 
small ones, nor vice versa. All the torches named are intended 
for oxygen and acetylene, except where mentioned otherwise. 
A number of different tips designed to be used with the torches 
illustrated, are shown in Fig. 28. 

The approximate pressures of oxygen and acetylene as used 
in the Davis torches are given in Table III. The tips referred 
to in compiling this table are known as styles Nos. 99 and 100, 



LARGE STYLE 
AftB TIPS 






^ aiip 


SHALL ST'rLf. 
A6rB TIPS 


G^^igiD 




STYLE B 


< — -9llP 




PENCIL TORCH 
WELD TIP 


^ c^ 




WATER COOLED 
HAND tVELD TIP 


CI , 1 [p 


WELDING 


WATER COOLED 
MACH WELD TIP 


CI 1 |> 


FOR riACHINE 
WELDING 


niDCET TIP 


czzHi^iD 




OXY.-HYDRIC 
WELD TIP 


=S 




OXY- ACET 
WELD TIP 


c — Zl 


1" LONG 


OXY- ACET 
WELD TIP 




nULTIPLE FLAME 






OXY -ACET 
WELD TIP 






C 1 \^l 




SMALL STYLE 
"CWELD TIP 


c=:a3D 




LARGE STYLE 
"C WELD TIP 


cmOZBDo 




L,-,RGE "C" 
WATER COOLED 


oi ff::^ 





SHALL't TIP 
FOR CITY GAS 



STYLE "G" 
WELD T;P 



W 



\ 



^ 



c==XBD 



CBo 



OD 



HID 



C=ZZI33 



c:^=a> 




FOR CI ■ ■■ GAS 



flULTIPLt FLAME 



CHICAGO STYLE 



Fig. 28. — Different Kinds of Tips Used with Davis-Bouinonville 
Welding Torches. 

and are used with style C torches. These pressures serve only 
as approximate guides and are not to be taken literally in 
practice. 

The Prest-0-Lite Torch. — The torch shown in detail in 
Fig. 29 is made l)y the Prest-0-Lite Co., Indianapolis, Ind., 
but is handled by the Oxweld Acetylene Co. This torch is 
fitted with a long stem through which the gases pass and are 
thoroughly mixed before issuing from the nozzle. 

The stem is fitted to the mixing chamber by means of a 
union nut, which permits the operator to point the welding 
tip in any direction, without changing his method of holding 



GAS TORCHES USED FOR WELDING 



59 



the torch. This is particularly advantageous for vertical and 
overhead welding. Both oxygen and acetylene inlets on the 
torch are fitted with fine-adjustment control valves. The one 
on the oxygen supply is so placed that the operator while 
working can make any slight necessary adjustment with the 
forefinger of the hand that grips the torch. The handle of 
the torch is fitted with anti-fireback chambers for both gases, 
filled Avith a special material through which it is impossible 
for a flame to pass. 



'iABLE III. — Approximate Gas Pressures for Davis-Bournonville 
Style C Welding Torch, With Nos. 99 and 100 Tips 





Thickness 


Acetylene 


Oxygen 


Tip 


of Metal 


Pressure 


Pressure 


No. 


Inches 


Lbs. 


Lbs. 


00 


/Very\ 
I Light] 


1 


1 


c 


1 


2 


1 


^-M 


1 


2 


2 


M-^ 


2 


4 


3 


■h-y% 


3 


6 


4 


y%-% 


4 


8 


5 


H-'A 


5 


10 


6 


%-% 


6 


12 


7 


A-'A 


6 


14 


8 


'A-Vs 


C 


16 


9 


Vs-H 


6 


18 


10 


M-Up 


6 


20 


11 


/ Extra\ 

\Heavy/ 


8 


22 


12 


8 


24 



The torch is easy to dismantle, as all parts are screwed 
together on metal-to-metal seats and no packing or solder is 
used at any joint. 

For extra heavy work, a special stem 22 in. long is fur- 
nished, and for close work a 5^-in. stem may be had in addi- 
tion to the regiilar size. The regular stem has seven tips, 
the largest four being of copper which will stand up against 
the intense heat radiated from the work better than any 
other metal. The smaller tips are of a special alloy. A 
similar torch is also made for very light work which weighs 
only 3 oz. complete. 

In the detailed view given of the torch, A is the hose nipple 



60 



GAS TORCH AND THERMIT WELDING 



through which the oxygen passes. At B is a set of 40 strainer 
cloths for the oxygen filter chamber; C is the oxygen needle 
valve; D is the acetylene hose nipple; E is the acetylene 

Complete Oxygen 
I Valve Assembly 

C ^40 Pieces 




Complei-e Acefy/ene 
valve Assembly 



Fig. 29.— Details of Presto-0-Lite Type H Welding Torch. 




Fig. 30.— Torches Made by the General Welding & Equipment Co. 

pxyc^en Tube 





^ M C Acel-ylene Tube'' 



F F F 

Fig. 31.— Details of Torch Shown in Fig. 30. 

needle valve; F is the acetylene filter-chamber cartridge; G is 
the stem. The seven tips are indicated from IH to IH, and 
their openings can be determined from Table IV. This table 
is especially valuable in that the nozzle openings are shown in 



GAS TORCHES USED FOR WELDING 



61 



regular twist-drill sizes, furnishing an easy method of com- 
parison. The two tips given at the bottom of the table are 
extras, used for heavy work. The figures quoted in the table 
are based on straight work on steel plate, beveled when over 
I in. in thickness and welded without preheating. 

Table IV. — ArpiioxiiiATE Welding Results With Type H, Peesto-O- 

LrrE Touch 



Tip 
.No. 


Tip 
Drill 
Size 


Gas consumption 
Cu. Fl. per hour 


Thickness of 
Metal 


Blow-pipe pressures 
Lbs. per sq. in. 


Lineal feet 
welded 
per hour 


Oxygen 


Acetylene 


Oxygen 


Acetylene 


IH 


69 


3 to 4 


3 to 4 


^■. to i;^, in. 


2 to 3 


2 to 3 


30 to 35 


2H 


60 


6 to8i 


6 to 8 


i'ii lo ii in. 


2 to 3 


2 to 3 


24 to 32 


3H 


55 


10 to 12J 


10 to 12 


I to 3=5 in 


3 to 4* 


3 to 4 


12 to 16 


4H 


52 


12 to 21 


12 to 20 


A 'o s'i in- 


4 to 6 


4 to 5 


9 to 12 


5H 


49 


18 to 28 


18 to 26 


1 to i"c in 


5 (o 7 


5 to 6 


6 to 8 


6H 


44 


24 to 40 


24 to 38 


I to -j'o in. 


8 to 11 


8 to 9 


41 to 6 


7H 


35 


35 to 54 


35 to 50 


I in. and up 


10 to 15 


10 to 14 


2 to 3 


•7J 


35 


35 to 54 


35 to 50 


?. in. and up 


9 to 13 


9 to 12 


Not used 
on plates 


*8J 


31 


40 to 60 


40 to 55 


I in. and up 


9 to 14 


9 to 13 


Not used 
on plates 



The General Welding Co.'s Torch. — A welding torch made 
by the General Welding and Equipment Co., Boston, Mass., is 
shown in Fig. 30. Each torch is furnished with nine tips, 
affording a range equal to all ordinary welding jobs. In addi- 
tion, stems of different lengths may be had. In the illustra- 
tion, A is the body of the torch; B is the mixing chamber; C 
is a short stem, the use of which makes the entire torch 16 in. 
long; D is a medium stem, making the torch 22 in. long; E is 
a long stem, making the total length of the torch 30 in. 

Details of this torch are shown in Fig. 31. Here the acetylene 
inlet is shown at A and the oxygen inlet at B. The body of 
the torch is indicated by C, and D is the mixing chamber ; E is 
the stem, and F various shapes of tips. 

Imperial Torches. — Another long-stemmed torch is shown 



62 GAS TORCH AND THERMIT WELDING 

in Fig. 32. This is made by the Imperial Brass Manufacturing 
Co., Chicago, and differs but little from the one just shown. 
The gas valves, however are placed at the forward end of the 
body. Like most of the other torches, these may be used not 
only for oxy-acetylene, but also for oxy-hydrogen welding work, 
special tips and regulators being made for the purpose. For 
oxy-acetylene, the gas pressures are approximately the same 




Fig. 32.— Tho Imperial Type B Welding Torch. 

as for other makes of torches. For oxy-hydrogen, the pressures 
used for various thicknesses of metal and different tips are given 
in Table V. However, neither the size of the nozzle holes nor 
the amount of gas used per hour are given. This firm also 
makes a three-way torch which in outward appearance does 
not differ from the one shown. It is intended to use a com- 
bination of acetylene, oxygen and hydrogen. The method used 

Table V. — Pressure of Gas Used in I>rpERiAL Oxy-Hydrogex 
WIELDING Torches 







Tl 


ickness of Metal 


Pressure, 


LI). 


Weldin- Tip 


No. 


tn 


be Welded, In. 


Oxygen 


PI 


ydrogen 


III 






1/64 to 1/32 


10 




10 


2H 






1/32 to 1/lG 


12 




12 


3H 






1/lG to 1/4 


15 




15 


4H 






\/\ to 1/2 


20 




20 


r.i-i 






1/2 in. niid up 


o- 




25 



is to couple the acetylene and hydrogen hose by means of a 
Y mixing valve from which the two gases are conducted by a 
single hose to the torch, the oxygen hose being coupled in the 
usual way. This concern does not recommend the welding of 
steel above \ in., or cast iron above '\ in. in thickness with 
oxy-hydrogen. For light sheet steel, and especially aluminum, 
oxy-hydrogen has some advantages, provided the hydrogen can 
be obtained at reasonable rates. The combination of oxygen- 



GAS TORCHES USED FOR WELDING 63 

aectylciie-liydrogeu, however, has a claimed temperature of 
about 5000 deg. F., which is about half-way between that of 
oxy-hydrogen and oxy-acetylene. It is also claimed that this 
flame possesses all the advantages of both the double combina- 
tions. The same tips are used as for oxy-acetylene, and only 
a small percentage of acetylene is needed to give a cone-shaped 
flame of far greater visibility than that of the oxy-hydrogen 
flame. The low visibility and long flame of the oxy-hydrogen 
flame are always a handicap in welding to any operator used 
to employing the oxy-acetylene torch. The approximate pres- 
sures employed Avhen using the Imperial three-way outfit are 
shown in Table VI. 

Table YI. — 1'kessukes of Gas Used in Imperial Thkee-Way 

Welding Touches 

Oxygen, Acetylene and Hydrogen 



Oxygen, 














Welding Tip, 


Thi^ 


L'kness of ]Metal, 




Pressures, Lb. 




No. 


to 


be 


Welded, In. 


Oxygen. 


Acetylene, 


Hydrogen. 


IT 






1/32 


3 


2 


f^ 


2T 






1/16 


5 


3 


3 


3T 






3/32 


6 


4 


4 


4T 






1/8 


7 


5 


5 


5T 






1/4 


8 


6 


6 


6T 






3/8 


9 


7 


7 


7T 






1/2 


10 


10 


10 


8T 






5/8 


12 


12 


12 


9T 






3/4 


14 


14 


14 


lOT 


1 


in 


. and over 


IS 


15 


15 



Calculating Amount of Gas. — It should always be borne in 
mind, when consulting a table where only pressures are. given, 
that these pressures do 7iot signify the amount of gas used, and 
that such pressures apply only to the particular make of torch 
mentioned. It might be possible for two different torches to 
use gases at exactly the same pressures as far as the gages 
indicated, and yet have one of these torches use several times 
the amount of gases used by the other. In order to make it 
possible for a user to estimate the amount of either oxygen or 
acetylene his outfit is consuming, three methods of estimating 
are given here. These methods are taken from the Prest-0-Lite 
instruction book. Other methods have previously been given 



64 GAS TORCH AND THERMIT WELDING 

in the descriptions of the different gases and their production. 
The Prest-O-Lite methods are : 

Method 1. — Weigh your acetylene cylinders before starting work. 
Weigh again after the job is completed. Note the difference in weight 
in ounces, and multiply by 0.9 ; result equals the cu.ft. of acetylene 
used. When UJiing Prest-(;)-Lite torches multiply the acetylene used 
in cu.ft. by 1.1 ; the result equals the eu.ft. of oxygen used. 

Method 2. — Take readings of oxygen cylinder pressure gage in 
atmospheres before and after. 

For 100-cu.ft. cylinders the difference of readings in atmospheres 
multiplied by 0.S3 equals the oxygen consumption in cu.ft. 

For 200-cu.ft. cylinders the difference in readings in atmospheres 
multiplied by 1.G7 equals the ((jnsumptiou of oxygen in cu.ft. 

For 2.50-cu.ft. cylinders the difference in readings in atmospheres 
multiplied by 2.08 equals the consumption of oxygen in cu.ft. 

When using Prest-O-IJte torches, multiply the oxygen used in cu.ft. 
by 0.91 ; the result equals the acetylene consumption in cu.ft. 

Method 3. — Measure drill size of orifice in torch tip. using standard 
drills for measuring. 

Area of orifice in sq.in. multiplied by S3 ecjuals the acetylene con- 
sumption in cu.ft. per minute. 

Area of orifice in sq.in. multiplied l)y 91 equals the oxygen con- 
sumption in cu.ft. per minute. 

Note the minutes the torch is iu use and use the above figures to 
estimate gas consumption. 

Remember, the acetylene consumption cannot I)e accurately esti- 
mated from the pressure gage readings. 

In order to simplify the calculations in Method 3, the areas 
of the various orifices made with numbered drills are given in 
Table VII. This table was calculated by K. II. Condit, man- 
aging editor of the American MacMnisf, for both square inches 
and square millimeters. 

The Reg-o Welding Torch. — The Rego welding torch is 
made by the Bastian-Blessing Co., Chicago. The claim is made 
for this torch that it will not flashback under any condition — 
even if the tip is immersed in the molten metal, or if the head 
and tip are heated to a cherry red. The elimination of the 
flashback is accomplished, not by check valves but by balancing 
the pressure of tJie gases used. The tips used are of one-piece 
nickel-copper composition. This gives a harder tip than copper 
alone. The gases are mixed in the tip as shown in the illustration 
Fig. 33. By means of an expansion chamber within the tip 
itself, the gases are reduced in velocity as they come from the 



GAS TORCHES USED FOR WELDING 



65 



Table VII. — Areas of Drills froji 1 to SO Size in Sq.In. and Sq.MM. 
Manufacturers Standard 





Size of 








Size of 








Drill 


Area in 


Area in 




Drill 


Area in 


Area in 


No. 


in In. 


Sq.In. 


Sq.Mm. 


No. 


in In. 


Sq.In. 


Sq.Mm. 


1 


0.22S0 


0.04083 


26.35 


41 


0.0960 


0.007238 


4.670 


^ 


0.2210 


0.03836 


24.77 


42 


0.0935 


0.006860 


4.426 


3 


0.2130 


0.03563 


22.99 


43 


0.0890 


0.006221 


4.014 


4 


0.2090 


0.03431 


22.14 


44 


0.0860 


0.005809 


3.748 


5 


0.2055 


0.03316 


21.39 


45 


0.0820 


0.005281 


3.406 


6 


0.2040 


0.03269 


21.09 


46 


0.0810 


0.005153 


3.325 


7 


0.2010 


0.03173 


20.47 


47 


0.0785 


0.004831 


3.117 


8 


0.1990 


0.03110 


20.06 


48 


0.0760 


0.004536 


2.926 


9 


0.1960 


0.03017 


19.46 


49 


0.0730 


0.004185 


2.700 


10 


0.1935 


0.02940 


18.97 


50 


0.0700 


0.003848 


2.483 


11 


0.1910 


0.02865 


18.48 


51 


0.0670 


0.003526 


2.275 


12 


0.1S90 


0.02806 


18.10 


52 


0.0635 


(».()( »:u 67 


2.043 


13 


O.lSoO 


0.02688 


17.34 


53 


0.0595 


(».(l()2781 


1.795 


14 


0.1S20 


0.02602 


16.79 


54 


0.0550 


0.002376 


1.533 


15 


O.ISOO 


0.02545 


16.42 


55 


0.0520 


0.002124 


1.370 


16 


0.1770 


0.02461 


15.88 


56 


0.0465 


0.001693 


1.092 


17 


0.1730 


0.02351 


15.17 


57 


0.0430 


0.0014.52 


0.9368 


IS 


0.1695 


0.02256 


14.56 


58 


0.0420 


0.001385 


0.8930 


19 


0.1660 


0.02164 


13.96 


59 


0.0410 


0.001320 


0.8510 


20 


0.1610 


0.02036 


13.14 


60 


0.0400 


0.001257 


0.8115 


21 


0.1590 


0.01986 


12.81 


61 


0.0390 


0.001195 


0.7710 


22 


0.1570 


0.01936 


12.49 


62 


0.0380 


0.001134 


0.7316 


23 


0.1540 


0.01863 


12.02 


63 


0.0370 


0.001075 


0.6936 


24 


0.1520 


0.01815 


11.71 


64 


0.0360 


0.001018 


0.6568 


25 


0.1495 


0.01755 


11.32 


65 


0.0350 


0.000962 


0.6207 


26 


0.1470 


0.01697 


10.95 


66 


0.0330 


0.000855 


0.5516 


27 


0.1440 


0.01629 


10.51 


67 


0.0320 


0.000804 


0.5187 


28 


0.1405 


0.015.50 


10.00 


68 


0.0310 


0.000754 


0.4865 


29 


0.1360 


0.01453 


9.374 


69 


0.0292 


0.000669 


0.4316 


30 


0.1285 


0.01296 


8.361 


70 


0.0280 


0.000615 


0.3968 


31 


0.1200 


0.01131 


7.297 


71 


0.0260 


0.000.531 


0.3426 


32 


0.1160 


0.01057 


6.819 


72 


0.02.50 


0.000491 


0.3168 


33 


0.1130 


0.01003 


6.471 


73 


0.0240 


0.000452 


0.2916 


34 


0.1110 


0.009677 


6.243 


74 


0.0225 


0.000398 


0.2.565 


35 


0.1100 


0.009503 


6.131 


75 


0.0210 


0.000346 


0.2232 


36 


0.1065 


0.008908 


5.747 


76 


0.0200 


0.000.314 


0.2026 


37 


0.1040 


0.008495 


5.481 


77 


0.0180 


0.000254 


0.1639 


38 


0.1015 


0.008092 


5.221 


78 


0.0160 


0.000201 


0.1297 


39 


0.0995 


0.007775 


5.016 


79 


0.0145 


0.000164 


0.10.58 


40 


0.09S0 


0.007543 


4.866 


80 


0.0135 


0.000143 


0.09226 



mixing chamber, and just before they issue from the end of 
the tip. This produces a ''soft" flame which melts the metal 
without blowing it away. 



66 



GAS TORCPI AND THERMIT WELDING 



The Oxweld Low-Pressure Torch. — The Oxwolcl low-pres- 
sure torch is of the true iujector type. One of this make of 
torch is shown in Fig. 34 and in detail in Fig. 85. In this 
torch the acetylene is drawn into the combining tube by the 
injector action of the high-pressure oxygen jet, in the proper 
quantity to form what is known as a neutral flame ; that is, one 




Fig. 33.— The Rego Welding Torch. 

not having an excess of oxygen or acetylene. A torch of this 
type may be used with either a low- or positive-pressure acety- 
lene system, although primarily designed for low-pressure 
acetylene, which means at a pressure of 1 lb. or less. Ten 
hard-drawn copper tips, shown in Fig. 36, are regularly sup- 
plied for this torch, and bodies may be had to hold the tips 




Pig. 34. — The Oxweld Low-Pressure Welding Torch. 



3 3 13 1 

T6> 64 > 32) 8) 16» 4' 



i 5. and 

,2)8 



at 67| or 90 deg., although the regular angle is 45 deg. The 
tips shown are numbered 2, 3, 4, 5, 6, 7, 8, 10, 12 and 15 and 
are intended for use on metal 
5 in. thick and up, respectively. 

A very light torch, weighing 9 oz. and known as model G, is 
shown in Fig. 37. This is intended for very light sheet metal, 
instruments, jewelry and the like. In order to secure a torch 
of minimum weight, the oxygen and acetylene regulating valves 



GAS TORCHES USED FOR WELDING 



67 



have ))ecn removed from the body of the torch and incorporated 
ill a separate valve block which may bo fastened in any con- 
venient position near the operator. 

Another very light torch is shown in Fig. 38. This is suit- 



Oxygen Va/ve^, ,VcPi/ve Body Oxygen Tube^^ 



Oxygen 
Hose- 
Connection 



Acetylene 
Hose Conn. 




Oxygen Chamber 
'Injector 

"Acetylene 
Chcpimber 

'Mixing 
ChitPimber 



Acet-ylene 
Voilve 

Fig. 35.— Details of the Oxweld Welding Torch. 



able for metals up to \ in. thick. In addition to the usual 
practice of placing needle valves in the rear body, there is also 
incorporated in the torch head a needle valve which gives minute 
control of the flame with each size of tip. Three sizes of in- 




FiG. 36.— A Set of Oxweld Welding Tips. 



terehangeable copper tips are supplied. It is 10 in. long and 
weighs 10 oz. 

The Oxweld water-cooled machine torches are shown in 
Figs. 39 and 40. Fig. 39 is a single-jet, known as type W-8, 



68 



GAS TORCH AND THEIUMIT WELDING 



o 
o 



3 



o 

u 
a> 
Ph 



g "=" 2 












CO 



P-,h:i 



.is *» 



%5 









iOOOO'-iC0«0-^Tt< 



OOOOOOOO^Cl 






OOOOO'-iiNiO'-HCOO 
i-HCOO 



^ (MCOOOlCOt^t-iOC^ t^. 



CO(N(NCO(N(NCOCCCO'*CO 



CO TJH CO 00 O •^ 00 CO ■* o CD 
.-( rH rH (N CC lO CO 



iOiOcOI>000(McDOOOI> 



CC^OOOOiOOll^COC^OS 
■-I —< '-i(N CO O CO 



:^ 



C0(Nr^-<^i-(05t*'1*C0>— i-l 
<N (M »-( 1— I t-H 



O CO ^ t^ -* 1-f OlCO •^ (N c* 

CO <M (N —i rH i-l 



to050'-iC<l"^COOi«-HiOO 
rHi— i.-(i— ii— (1— iC^C<cO 






1*3 -gfl 



O 



ffl(NC0T}<iOCDI>00O(M»O 
'O I— 1 1— 1 1—1 

o 



00<N<OCOi-< 
C^KMi-ii-i-H 

6 6 6 6 6 



\ -M-^-^-^^-^^^-^^ 



GAS TORCHES USED FOR WELDING 



69 



and is adapted to work on cartridge cases, pistol magazines, or 
any light sheet-metal work that can be fed mechanically. Fig. 




Fig. 37.— The Oxweld Welding Torch Model G. 




Tig. 38.— The Oxweld Sheet-Metal Welding Torch 




Fig. 39.— The Oxweld AVater-Cooled Single-Jet Welding Torch, Type W-8, 



40 is known as type W-5, and is a multiple-jet torch suitable 
for Yielding metal up to ^/^. in. thick, and is designed for con- 



70 



GAS TORCH AND THERMIT WELDING 



tiniious operations on tube stock or other mechanically handled 
work. 

In Table VIII, which is taken from the Oxweld handbook, 
the various thicknesses of metal, the oxygen pressure, hourly 







Ttt£;SS;S 











Fig. 40.— The Oxweld Water-Cooled Multiple-Jet Welding Torch, Type W-5. 

gas consumption, consumption per foot and amount of wire 
used, are shown. In this table the acetylene is used at 1-lb. 
pressure. 

The Messer Torch. — The torch shown in Fig. 41 and in 




Fig. 41. — The Messer Welding Torch and Tips. 

detail in Fig. 42 is made by the Messer Manufacturing Co., 
Philadelphia, Penn. It works on the injector principle and 
may be used with either low- or positive-pressure acety- 
lene systems. This make is notable on account of the single 
valve in the torch itself, and the tips, which are bent, may be 



GAS TORCHES USED FOR WELDING 



71 



sot at any angle radial with the torch body. The various sizes, 
tips and general range arc practically the same as for the torches 
jtrevioiisly described. 

The Oxy-Thermalene Welding Torch. — An oxy-thermalene 
welding torch and a set of tips, are shown in Fig. 43. Details of 
the head are shown in Fig. 44. One of these torches is about 
17 in. long and weighs 24 oz. Referring to the detailed cut, the 




Fig. 42. — Details of the Messer Welding Torch. 



oxygen enters at A and the thermalene at B. The oxygen 
nozzle is at C. Screens are placed at D. One of the troubles 
with some torches is the fact that frequently a flashback will 
occur, reaching the oxygen nozzle in the gas chamber. Here a 
flame would be formed which would burn out the entire copper 
tip. In the torch shown it is claimed this does not occur. It 
will lie seen that the gas chamber is comparatively large, while 




Fig. 43. — A Thermalene Welding Torch and Tips. 

the orifice leading from the gas chamber to the mixing chamber 
is restricted and elongated. This orifice is enlarged abruptly 
to the mixing chamber in the nozzle, so as to form sharp 
corners at E. The mixing chamber gradually contracts to the 
outer opening in the nozzle. As a result, if a flashback should 
occur, it will cause a whirl or eddy at the shoulder E, which 
in itself will prevent the flame from running back through the 
restricted channel. Moreover, such propagation of the flame 
into the mixing chamber will cause the gas in the chamber to 



72 



GAS TORCH AND THERMIT WELDING 



be pressed back by the increased expansion and pressure, 
so that there will be only Inirnt gas in the restricted channel 
and around the oxygen tip. The result is that the flame will 




Fig. 44. — Details of the Thermalene Welding Torch Head. 

die out in the restricted channel between the gas and mixing 
chambers, so that a cutting flame is never formed at the oxygen 
nozzle. It is necessary, however, that these parts should be 
properly proportioned to obtain the desired results. 



Table IX. — Amount of Oxygen and Thermalene Used foe Welding 







Thick- 


Consump- 


Consumption 


Oxygen 






ness of 


tion of 


of Oxygen 


Pressure. 






Metal 


Thermalene, 


with Therma- 


with Therma- 




Tip No. 


in Inches 


Ft. 


lene. Ft. 


lene, Lb. 




1 


Ato,^ 

5feto A 

Ato i 
1 to^ 


2.15 
3.32 
5.51 
8,29 


2.55 

3.99 

6.52 

10.11 


1.0 




2 


2^0 3 




3 


3 to3i 




4 


3J to 4i 




5 


Ato^ 


11.78 


14.21 


5 to5| 




6. 


AtoiV 


16.48 


20.10 


6i to 7i 




7 


T^tof 


21.40 


27.51 


10 to 11 




8. 


1 toi 


25.00 


35.01 


11 to 12 




9 


i to J 


33.60 


54.21 


15 




10 


i toli 


48.05 


75.30 


20 to 22 




11 


Uto If 


70.35 


101.62 


25 to 28 




12 


1! to2 


91 . 10 


159.20 


25 to 30 



For various welding purposes, 12 sizes of tips are made to 
be screwed into the torch bodies. These tips run from 2 to 4 
in. in length, and the outlets vary from the size of a No. 80 



GAS TORCHES USED FOR WELDING 73 

to No. 33 drill. All have ^/le-in wrench-holds on them for 
screwing into the torch bodies. 

Table IX will furnish a good idea of the amount of therma- 
lene and oxygen used per hour for different thicknesses of 
metal, the torch being fitted with the proper nozzle in each case. 



CHAPTER VI 
GAS CUTTING-TORCHES 

The gas cutting-torch is coiunionly used for cutting through 
various thicknesses of steel or wrought iron, which are the only 
metals which can be satisfactorily or economically cut by this 
process. Cast iron cannot be satisfactorily cut with a gas torch. 
As an adjunct to a welding outfit, the cutting-torch is used for 
beveling and for cutting out patches and holes. The process is 
based on the fact that a jet of oxygen directed upon a previously 
heated spot of iron or steel, causes it to ignite with the result 
that the metal, acting as its own fuel, burns away rapidly in 
the form of iron oxide. This oxide runs, or is blown, out of 
the cut or kerf produced, in a stream, provided the torch is 
fed along properly. The same sources of gas supply may be 
used as for welding, though in some cases other regulators must 
be employed. 

As previously stated, steel and wrought iron are the only 
metals which can be satisfactorily cut by this process. The 
reason is that these two metals combine readily with oxygen, 
with the liberation of heat. The slag is produced at a tempera- 
ture below that of the melting point of the metal, with the result 
that it is easily separated from it. Other metals do not produce 
so much heat when combining with oxygen, and the oxide formed 
is not reduced to a molten condition at temperatures below that 
of the melting point of the metal, with the result that it cannot 
be easily separated. 

The combination of the oxygen with the iron is not that of 
complete combustion. An examination of the slag produced 
shows the presence of metallic iron, which leads to the belief 
that the oxidation follows the grain surfaces of the metal and 
more or less mechanically disintegrates the mass at the line of 
cutting. 

Cutting torches use a single high-pressure oxygen jet for the 

74 



GAS CUTTING-TORCHES 



75 



cutting. This jet has one or more heating jets in line with, or 
surrounding it. 

Since the temperature to which it is necessary to heat the 
iron or steel, in order to have the oxygen act, is comparatively 
low (about 900 cleg. F.) a number of gases may be used for 
heating. Oxy-acetylene is very commonly used on account of 
its convenience, for ordinary work. For heavy work oxy- 
hydrogen is used on account of its longer flame and because 
no products of combustion that hinder cutting are produced. 
The temperature required is well .within its heating range, 
and steel up to 36 in. thick has been cut. The thicker the 
metal the greater the pressure of oxygen used, as will be seen 



PREHEATING OXYGEN VALVE 




OXYGEN 
"^^^^mACETYLEN 
'^ACETYLENE VALVE 



REMOVABLE PLUG 



I ,.,,,, CUTTING VALVE 

■ I'liip'. TRIGGER 

;';|iMi', C /Remains in open Position) 
"i,''.i'„i 

Fig. 45.- — Details of the Davis-Boiirnonville Cuttinij Torch. 



from the various tables. In the cutting torches, the holes for 
the various jets are usually drilled in the same tip, though in 
some cases separate tips, set close together, are used. The 
ordinary cut or kerf made by the cutting torch is from ^/j,. 
to -g in. wide, according to the size of the oxygen jet used. 

Since the same construction of the heating part of a cutting- 
torch is used as in the welding torch, it naturally follows that 
both the positive-pressure and low-pressure, or injector types 
of heating units are used in conjunction with the single oxygen 
cutting jet. 

The Davis-Boumonville Cutting Torches. — The details of 
a Davis-Bournonville, No. 3000, cutting torch are shown in 
Fig. 45. This is typical of the general principle on which all 
of this firm's cutting torches are made. In use, the positive- 



76 



GAS TORCH AND THERMIT WELDING 



pressure heating unit is first started and applied to the work 
to be cut. As soon as the metal reaches a red heat, the trigger 
is pressed and the oxygen jet commences its work. This par- 
ticular model of torch is supplied with five interchangeable 
tips, and the cutting jet of oxygen may be turned on or off 
by a simple pressure of the trigger, as just mentioned. This 
trigger is so made that it is not necessary to keep the finger 
on it all the time it is in use. There are only two hose con- 
nections for the gases, one for oxygen and one for acetylene. 



=€1 



T 




Fig. 46- — Various Models of the Davis-Bounionville Cutting Torches. 



The pressures of the respective gases vary with the thickness 
of the metal being cut, which may be from ^ up to 12 in. or 
more. The torch is 20 in. over all, and is especially adapted 
to freehand cutting, and in wrecking or scrapping metal. 

A number of different styles of cutting torches arc sliown 
in Fig. 46. A is a straight-head cutting torch (No. 2018) 
which may be fitted with curved tips for cutting Ijoiler tubes, 
rivet heads, etc. Three bent and two straight tips are regu- 
larly furnished. In general, it closely resembles No. 3000. • 

The torch B, known as No. 1316, is very much like the first 
torch described, except it is intended for use with oxy- 



GAS CUTTING-TORCHES 



77 




5 



>:-^ 






0)5 



gs 



\J 



Si 

1; 






■t^ 



Js^ 






^ lA 



t\j "^vj 



J3 









Si 

'J- 



V7 







^1 

5^ 






D 



)(IB 



OD 



s: 



kg 






§S 






m 



^ 



78 



GAS TORCH AND THERMIT WIELDING 



liydi'ogx'ii. Torch C (No. 471) is a circle cutting torcli tittccl 
witli a 15-in. radius rod adjustable for various sizes of circles. 
It uses either oxy-acetyleiie or oxy-hydrogen for heating, and 
takes all standard size tips. It is the standard torch for nick- 
ing billets for breaking. It may be had fitted with special 
adjustable holder, rack and pinion, for machine cutting. 



Tahle X. — Gas Pressures Used With the Davts-Bournonville Style 
C Cutting Torches, Using Style 12 Tips 





Thickness 


Acetylene 


Oxygen 


Tip 


of Metal 


Pressure 


Pressure 


No- 


Inches 


Lbs. 


Lbs. 


1 


Vs 


3 


10 


1 


% 


3 


15 


1 


M 


3 


20 


1 


% 


3 


20 


2 


Va 


3 


10 


2 


Vi 


3 


20 


2 


M 


3 


30 


2 


1 


3 


35 


3 


1 


4 


30 


3 


1^ 


4 


40 


3 


2 


4 


50 


3 


3 


4 


60 


4 


3 


5 


60 


4 


4 


5 


70 


4 


5 


5 


85 


4 


6 


5 


100 


5 


6 


6 


90 


5 


7 


6 


100 


5 


8 


6 


125 


5 


10 


8 


150 



Torch P, No. 640, is a machine cutting torch for use with the 
different cutting machines made by the Davis company. It 
is fitted with an electric switch and shut-off valve which auto- 
matically starts the cutting-machine feed wheii the oxygen 
cutting jet is turned on, without the necessity of readjusting 
pressures or the heating flame. It uses all standard-size cutting 
tips and special Oxygraph and Radiograph tips. A larger and 



GAS CUTTING-TORCHES 



79 



heavier torch of similar dosign and construction for oxy- 
hydrogen machine work is shown at E. .This is known as 
No. 1314. Larger sizes, or special torches used for cutting, 
are water-cooled. Tips of various styles, for different pur- 
poses, which may be used with the torches mentioned, are 
shown in Fig. 47. 

The approximate oxygen and acetylene pressures used in 




Fig. 48.— The Oxweld Cutting Torch, Model B. 

the Davis style C cutting torches, using style No. 12 tips, are 
given in Table X. As in welding, these pressures are only 
general guides for the make of torch mentioned, and the 
skilled operator usually adjusts his flame regardless of the 



Oxycjen 




Pre-heat-incj Ve/s— - 

Fig. 49.— Details of the Oxweld Cutting Torch, Model B. 

tables given, since a neutral heating flame is essential at all 
times for satisfactory results. 

Oxv/eld Cutting Torches. — An Oxweld low-pressure or in- 
jector type of cutting torch is shown in Fig. 48. This is their 
model B. Details are shown in Fig. 49. In this torch, the 
cutting jet is entirely surrounded by the preheating flame, as 
the oxy-acetylene is delivered through six openings arranged 



80 GAS TORCH AND THERMIT WELDING 

in a circle around the orifice for the oxygen jet. This arrange- 
ment makes it possible for the preheating flame to always 
precede the cutting jet, no matter in what position the torch 
is held, or in wliatever direction the cut is made, be it hori- 
zontal, transverse, circular, elliptical, toward or away from 
the operator. In so woi'king, the operator does not have to 
sliift his postion or turn the torch. This is especially valuable 
in wrecking steel structures, removing risers from steel cast- 
ings, or cutting steel scrap, especially where places difficult 
of access are encountered. The preheating flame is produced 
in practically the same way as in tlie welding torch previously 
shown. 

There is a separate valve for controlling the oxygen to the 
preheater, wliich enables tlie operator to secure close adjust- 
ment and avoid waste of gas. The oxygen-jet valve is of the 




Fig. 50. — The Oxweld Cutting Torch with a Eivet-Head Cutting-Nozz]e. 

plunger type, which is so constructed that its movement pro- 
duces no tendency to deflect tlie cutting jet from the line of 
the cut. The location of the valve lever is on top of the 
handle and its motion is in the direction of the vertical center 
plane of the torch. The valve is held open for continuous 
cutting, when desired, by a simple but effective button-like 
latch, which may be instantly engaged or released by a slight 
movement of the thumb. The external nozzle is furnished 
with a copper tip. The internal nozzle is held in place by 
tightening the external nozzle. To remove the former it is 
only necessary to unscrew the external nozzle. This torch is 
regularly furnished with four interchangeable tips, for cutting 
up to 1 in. ; from 1 to 3 in. ; from 3 to 6 in. ; and from 6 in. up. 
A model-B torch fitted with a special rivet-head cutting 
nozzle is shown in Fig. 50. Another form, known as model 



GAS CUTTING-TORCHES 



81 




Fig. 51.— The Oxweld Cutting Torch for Ship Work. 




Fig. 52.— The Oxweld Staybolt Cutting-Torch. 



82 GAS TORCH AND THERMIT WELDING 

C-6, is sliown in Fig. 51. This was made to meet tlie demand 
for a light, rugged and adaptable cutting torch for work on 
double bottoms and below decks of ships. In general, it closely 
resembles the other models. It weighs 2^ lb. and is 20 in. 
overall.. 

For cutting inner and outer shells of locomotive fireboxes, 
where length and slenderness is necessary, the staybolt cutting 
torch shown in Fig. 52 has been made. This is, however, 
merely a special form of the model B. The long "stem" is 
made up of three gas tubes as shown. Tliis torch is regularly 
furnished in 42, 54, 69 and 84 in. lengths to suit the needs of 
the user. Tlie 84-in. torch weighs 6^ lb. The head is set at 
an angle of 20 deg., which experience has shown is the more 
generally useful. All the regular nozzles can be used with 
this torch. 

In addition to the torches mentioned, the Oxweld Acetylene 
Co. makes straight-tipped machine cutting torches, which may 
be used on any of the cutting machines on the market. Like 
all other cutting torches, small guide wheels may be used for 
steadying the torch when cutting to straight, irregular or 
circular lines by hand. 

In Table XI are given the oxygen pressures and amount of 
gas consumption for various thicknesses of metal. The acety- 
lene pressure is the same as for welding, 1 lb. With the data 
given in tliis table, and knowing the cost of acetylene and 
oxygen, the approximate cost of gas for any given job may 
be calculated with a fair amount of accuracy and serve as a 
basis for price estimates. It must be kept in mind that old 
rusty metal, like boiler plate, will take much more gas than 
will clean metal. 

Other Cutting- Torches. — In order to give tlie reader an 
idea of the construction of some of the other well-known cut- 
ting torches, a few will be shown. Fig. 53 shows details of 
a cutting torch made by the Messer Manufacturing Co., Phila- 
delphia. This type of torch will use either medium or low- 
pressure acetylene, as it works on the injector principle which 
is independent of the acetylene pressure. The oxygen jet is 
operated by means of the lever shown on top. The wheel 
guides are adjustable so that the tip may be kept the proper 
distance from the work. ' 



GAS CUTTING-TORCHES 



83 



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84 



GA8 TORCH AND THERMIT WELDING 



The construct ion of the cutting torch made l).y tlie General 
"Wekling and Equipment Co., lioston, Mass., is sliown in Fig. 
54. The valve lever for the cutting jet has a lock tliat is 
easily manipulated with the thumb. This torch will use cither 
medium- or low-pressure acetylene, and like the other torches, 
will use either acetylene or hydrogen with the oxygen. The 



( () ,( ) . 0) 




Fig. 53. — Details of the Messer Cutting Tools. 




© ® POINTED 

MO I NoZ 'JOZZLf 



® © 5TD 

No 5 A No 4 A NOZZLE 



STAYBOa 
NOZZLE 



FiCx. 54. — Details of the Cutting Torch Made by the General Wekling and 

Equipment Co. 

parts are easily changed when necessary. The head is fastened 
to the mixing chamber by means of a ground-joint swivel and 
loose-nut coupling. The swivel is brazed into the head so 
as to make a tight joint even under heat. The mixing chamber 
can be easily taken out and cleaned. The lever key is accessible 
from all sides and the seat can be replaced in a few minutes. 
As has been previously mentioned, the consumption of the 



GAS CUTTING-TORCHES 



85 



various gases for different work can be only approximately 
estimated beforehand, as so many elements enter into the 
Avork. Even in cutting the same piece, if the cut is of any 
length, the gas consumption and time will often vary to a 
marked extent from different causes. Parts may be clean and 
others rusty. The operator's skill will vary as he is fresh or 
tired, and many other reasons may enter into the calculations. 
However, tabulations of specific results may often be of con- 
siderable value. Those already given have been for average 
conditions, and are believed to be as near correct as it is pos- 
sible to get them. The company making the torch last men- 
tioned has made some calculations regarding the time taken 
to cut clean metal, Avhich will be of interest. On |-in. steel, 
the time for cutting 1 ft. with a regular machine cutting tip, 
was 0.67 min. and by hand, 0.90 min. ; for 1-in. steel, 1.25 and 
1.50 min. respectively; for 2 in., 1.40 and 1.60 min.; for 4 in., 
1.50 and 2.00 min. ; for 6 in., 3.00 and 4.00 min. and for 8 in., 
3.25 and 4.50 min. 

An 8-in. steel shaft was cut through in 3 min., using 14 
cu.ft. of oxygen ; an 18-in. shaft was cut in 16 min. with 250 
cu.ft. of oxygen ; a 20-in. shaft in 18 min. and 300 cu.ft. of 
oxygen. For the last two oxy-hydrogen was used. 

The cutting of steel risers and shafts, under what is claimed 
to be average conditions, is tabulated as shown in Table XII. 
The tests are classified as follows : 

Table XII. — Cutting Steel Risers With the General Welding and 
Equipment Co. Torches 











i . 




1- 
3 








m 




*- 


Z" 


. 




TEST 




3 


« (- 


z 6 


I 


I 


ID 




SHAPE OF CUT 





3 3 


i Z 


i t 


- D 


Z 


NO. 




X Q 


t s 





< 

a 


U ^ 

3 a: 


i 






= s 


7 


3 




u 








z S 


H 5 


H U 


in a. 


(fl Q. 


H 


1 


Different shapes, 1 
1 in. to 5 in. thick ( 


40 


615 


248 


2.84 


- 


- 


2a ) 


Wheel rim 1 § in. 


( 10 


94.5 


8 


11.8 


22.5 


4.17 


2b \ 


to 23 2 in. thick 


\ 10 


100.6 


10.4 


9.67 


18.3 


5.5 


3 


6] 2 in. X 8 in. 




52 


14 


3.7 


27.1 


1.92 


t 


5 in. X 10 in. 




50 


18 


2.78 


20 


1.5 


5 


5', in. X IS '4 in. 




85.25 


34 


2.5 


22.8 


3.75 


6 


5L., in. X 15' , in. 




85.25 


28 


3.04 


26.2 


3.25 


7 


5I2 in. X 16 > 2 in. 




90.75 


^^2 


2.84 


27.9 


3.25 


8 


11 in X 11 in. 




242 


112 


2.16 


— 


— 


9 


6 in. diameter 




113 


46 


2.48 


11.3 


10.00 


10 


15 " 




177 


162 


1.1 


12.6 


14.00 


11 


16 " " 




200 


200 


1.0 


14.3 


14.00 


12 


18 '.'- " 




254 


250 


1.0 


15.9 


16.00 


13 


20 " «' 




314 


300 


1.05 


17.3 


18.00 



86 GAS TORCH AND THERMIT WELDING 

Test No. 1 comprises ordiiaary work as it came along. Risers were 
not clean and especially the smaller risers had sand and holes in the 
core. The oxygen consumption contains all the waste changing from 
one piece to another. 

Test No. 2a was made on clean metal with oxy-acetylene and with 
a special pointed tip. 

Test No. 2b was the same as No. 2a but cut with oxy-hydrogen, a 
regular tip being used. 

Test No. 3 was made on a very clean riser. The operator could rest 
his hand very comfortably. The cut looked as if it was done by 
machine. 

Tests Nos. Jf-7. — Cuts were made on risers of a 20-ft. flywheel. 
Cleaning was only superficially done and operator was in a fair, but 
not ideal position. One riser showed a large blow-hole. The cuts 
were clean through. 

Test No. 8. — Two cuts were made on the same flywheel. Risers 
were well-cleaned, but the cranes could not be spared to bring the 
face of the risers into a horizontal line. They had to be cut diagonally 
and the operator had to bend so far over that with the first riser he 
lost his balance and fell and had to interrupt the operation, therefore, 
no time was taken. The maximum thickness of the cut was 13 in. 
The cuts were clean through. 

Tests No. 9-13. — Cuts were made on risers of circular shape. The 
number of sq.in. cut per cu.ft. of oxygen is in the average lower than 
with rectangular shapes, as it is too cumbersome to regulate the 
oxygen pressure according to the varying thickness. It does not pay 
to start with lower pressure at the beginning and increase it the more 
the cutter is nearing the center or full thickness of the metal. More- 
over, the cuts were made with a two-line cutting torch so that the 
preheating flames would have suffered with regulating the oxygen 
pressure in such wide limits. With the heavier cuts of 15 in., 16. in., 
18 in. and 20 in. thickness, the principal consideration was to cut 
through rather than to get stuck, and not look too close to the oxygen 
consumption. 

The Imperial Brass Manufacturing Co., Chicago, makes the 
cutting torches shown in Fig. 55. These are of the positive- 
pressure type. A is a combination cutting and welding torch, 
the oxygen pipe and tip being detachable, so that the curve 
tip may be put on when the torch is wanted for welding. B 
is a cutting torch only. Either may be used for oxy-acetylene 
or for oxy-hydrogen. When using oxy-hydrogen, the respective 
pressures are given in Table XIII. 

The torches may also be used for the company's three-way 
gas system, which uses a combination of acetylene, hydrogen, 
and oxygen, as explained under welding torches. The acety- 



GAS CUTTING-TORCHES 87 

Taklio XIII. — I'i{ks,sui:e.s fou Oxy-IIyduookn Cutting with Impekial 

Touches 

Tliirkiif.ss of W'roUiuiit 
Cutting Iron or Steel . Pressures ^ 



Ti]i to be Cut, In. Oxygen, Lb. Hydrogen, I.b. 

Ill i to 2 30 to 40 5 to 10 

211 2 to 4 no to 70 10 to 15 

811 4 to 6 80 to 100 35 to 20 

4H G to 9 100 to 125 20 to 25 

5H 9 to 12 125 to 150 25 to 30 
These figures represent minimum and maximum pressures. For in- 
termediate tliicknesses use pressures in i)roportion. 

lene and hydrogen are mixed through a Y-valve and enter the 
torch through the same liose. Pressures when the gases are 
used in this way are shown in Table XIV. 

Table XIV. — Pressures When Using Three-Way Gas Sy'stem 





Tliiclaiessof 










Steel or 








Cutting 
Tip, No. , 


Wrought Iron 
to be Cut. In. 








Oxygen, Lb. 


Acetylene, Lb. 


Hydrogen, Lb. 


IT 


1 to 2 


30 to 40 


5 


5 to 10 


Oip 


2 to 4 


50 to TO 


5 


10 to 15 


3T 


4 to G 


80 to 100 


10 


15 to 20 


4T 


6 to 9 


100 to 125 


10 


20 to 25 


5T 


9 to 12 
and over 


125 to 150 


15 


25 to 30 



The Carbo-Hydrogcn Co., Pittsburgh, Pcnn., makes two 
models of the injector-type hand cutting torches, shown in 
Figs. 56 and 57, and in detail in Fig. 58. They also make 
straight -nozzle machine torches. 'Mechanical, guides, or wheels, 
may be had for attaching to the regular hand models, or to the 
straight-nozzle torches. Tips are furnished in a number of 
interchangeable sizes and shapes. They are made from a 
solid brass bar, with an outer shell of copper solidly attached 
with rivets. The preheating holes are arranged closely around 
the cutting orifice so that the flame cones do not have a 
tendency to melt edges of the cut. It is claimed that the tips 
remain cool and do not have to be dipped in water to keep 
them cool when used for long periods. The regular sizes of 
the tips are arranged for cutting from the thinnest metals up 
to 18 in. in thickness, or more with special tips. The head and 



88 



GAS TORCH AND THERMIT WELDING 



base castings of the torelies are of Tobiii bronze and the 
tul)es are of seamless drawn steel, surrounded by an aluminum 
or a fiber handle. A special swivel-point valve stem, instead 
of the usual solid needle point, is used for controlling the 




Fig. 55. — The Iiiipciial Cutting Torches 




Fig. 56. — Carbo-Hydrogen Model C Cutting Toioh 




Fig. 57. — Carbo-Hydrogen Model B Cutting Torch. 

combustion gas. All parts are easily removed for cleaning, and 
the injector may be taken out witli a pair of pliers. These 
torches are designed for use with oxy-carbo-hydrogen gas. 
Carbo-hydrogen is a fixed gas, permanent under all weather 
conditions. Since it does not solidify there is said to be no 
residue left in the tanks or cylinders at any time. Tt is clean, 



GAS CUTTING-TORCHES 



89 



easy to use, and safe, since it is combustible but not explosive 
within itself. It is a product of the destructive distillation 
of suitable hydro-carbons, and has a general analysis of 85 
per cent hydrogen and 15 per cent light hydro-carbons. It is 
claimed that this gas has no tendency to harden the surface 
of the metal being cut. It is not a sensitive gas, and backfiring 
is rare. It is marketed in steel cylinders under 1800 lb. pres- 



BASE CASTING 




Fig. 58. — Details of Carbo-Hydrogeu Cutting Torches. 

sure and of about the usual capacity. The pressure is reduced 
to from 5 to 10 lb. for working purposes, 5 lb. being the pressure 
usually employed. 

In Table XV are shown the approximate number of feet 
cut per hour, the pressure of the oxygen and the amounts of 
the gases used per lineal foot of cut. The carbo-hydrogen 
pressure is 5 lb. in each case. 

Table XV. — Gas Consumption and Pressures When Using Oxy-carbo- 

HYDROGEN CUTTING-TORCHES. ThE CaRBO-HYDROGEN PRESSURE IS 

About 5 Lb. in Each Case 



Thickness 


Size of 


Lineal Feet 


Pressure of 


Cu. Ft. of 


Cu. Ft. of Car- 


of Steel 




Cut per Hour 


Cuttinp Oxy- 


Oxygen Used 




in Inches 


Tip 


by Hand 


tren in Pounds 


per Lineal Ft. 
of Cut 


LTsed per Lineal 
Ft. of Cut 


J4" 


1 A 


110 


15 


1 


1 


M" 


2 


90 


25 


Iri 


1 


34" 


2 


75 


32 


2J^ 


IH 


1" 


2 


60 


35 


3 


\% 


IK" 


8 


45 


45 


47^3 


2J^ 


2" 


3 


38 


50 


7 


-iVz 


3" 


3 


28 


60 


14 


6 


4" 


3 A 


18 


75 


26 


9 


5" 


4 


13 


85 


32 


12 


6" 


4 


11 


100 


40 


13 


7" 


5 


8 


120 


50 


13 


8" 


5-A 


7 


140 


64 


14 


9" 


5-A 


ti 


160 


78 


16 



Above pressures can be increased at times on various grades of steel 
advantage. 



90 



GAS TORCH AND THERMIT WELDING 



The Rego cutting torch is made by the Bastian-Blessing 
Company, Chicago. Like the "balanced pressure" welding 
torch made by this concern, it is claimed that the cutting torch 
cannot be made to flashback while in use. Details of the 
mechanism are shown in Fig. 59. The tip is of nickel-copper 
composition and mates with a ground joint to which it is held 



REINFOKCED TUBES 



NO FLftSHBACK 




DING SLEKVE 



EEDLE VAUVeS 



Fig. 59. — Eego Cutting Torch. 



by a union nut. The mixing chamber is easily renewable. All 
valves are outside and easy to get at for repacking or re- 
grinding. The high pressure oxygen valve seat is metal to 
metal, and it is controlled by a powerful spring and is operated 
by a long lever acting on a plunger, like the valve of a gasoline 
motor. The operating lever is easily locked so there is no 
strain on the operator's hand. 



GAS CUTTING-TORCHES 



91 



Combination Torches. — Several companies make combina- 
tion welding and cutting torches. These usually consist of a 




B Vir:pif^fi£AriNO AND CUTTING 

Fig. 60. — Aireo-Vulcan Combination Cutting and Welding Torch. 




Fig. 61.— Milburn ''Cut-Weld" Torch. 




Fig. 61A.— Details of Milburn Torch. 




Fig. 61B.— Details of Torch Tip. 

cutting attachment for the welding torch. As a commercial 
proposition, such combinations are usually not to be recom- 
mended, but where an operator occasionally has to shift quickly 



92 GAS TORCH AND THERMIT WELDING 

from welding to cutting, they may sometimes be used to ad- 
vantage. Along with their regular lines of welding- and cut- 
ting-torches, the Air Reduction Sales Co., N. Y., put out the 
combination torch shown in detail in Pig. 60. This is known 
as the Airco-Vulcan cutting and welding torch, and it well 
illustrates the general principles of this kind of a torch. The 
main body is that of the regular Airco-Vulcan welding torch. 
The regular welding tip is removed from A to receive the 
connection of the special tip B. This tip is connected at C 
to the high-pressure oxygen tube D. A combination valve is 
screwed into the torch body at E in place of the single oxygen 
valve used for welding. This valve has a passage at F for the 
preheating oxygen and one at G for the cutting oxygen that 
goes out through D. Tlie preheating flame surrounds the cut- 
ting jet as in other regular cutting torches, so that an operator 




Fig. 62.— Torchweld Gas Cutting-Torch. 

may cut circles or angles without altering tlie direction of the 
torch body to any extent. 

The Milburn Combination Torch.— The "Cut-Weld" torch 
made by the Alexander Milburn Co., Baltimore, Md., is shown 
in Fig. 61. This torch is made into either a cutting or a 
welding torch by merely changing the tips. The illustration 
shows a cutting tip in place and a welding tip just at the left. 
The regular size is 19 in. long and weighs 2f lb. Details of the 
torch, with a cutting tip in place, are shown in Fig. 61A. De- 
tails of a welding tip are shown in Fig. 61B. 

In tests in Washington before engineers of the Stone & 
Webster Corp. and several government officials, a 12 in. steel 
billet was cut through in 6^ min., which includes ^ min. for 
preheating. A test was made to determine its resistance to 
backfire and though the tip Avas nearly burned ofp, no flashback 
took place. A hole was also blown through a 5 in. steel billet 
in 40 sec. with no flashback. 



GAS CUTTING-TORCHES 



93 



Torchweld Gas Cutting-Torch. — The gas cutting-torch 
shown in Fig. 62 is macU' by the Torchweld Equipment Co., 
Fulton and Carpenter Sts., Cliicago, and is known as their 
style 15 MC. It is designed to use oxy-acetylene, oxy-hydrogen, 
or oxy-hydrocarbon gases, such as butane, calorene, and the 
like. Special tips, however, are needed for the various gas 
combinations. An 85-deg. torch-head angle is standard but 
70, 50, 35 and straight heads can be furnished when desired. 

A one-piece cutting tip is used and the mixing chamber is 
just back of the torch head. A novel feature of the construc- 
tion is that an annular space is provided around the mixer in 
which a small amount of gases accumulate. Drill holes con- 
nect this space with the gas passage-way leading to the tip 
and, in case of backfire to the mixing chamber, the ignited 
mixture in the annular space is designed to blow out the back- 



Acetylene Tube 
Front HP 



HP \/a/^e Push Pop/., ^ HPPear Tube, . P'uq 
iPl/intve RocKer 



B.P Valine Pluncfer 




'tl.PVali'ePlunqei 

r, a /-« T- hPMivSeafOnly 

i--One Piece Cuttincj Fp 

Fig. G2J Details of Torchweld Cutting Torch. 



fire and eliminate the hazard of flashbacks into the flexible 
connecting hose. 

All the gas-tight seats in tips, needle valves and connec- 
tions, are of the line-contact type : In other words, a convex 
surface is brought into contact against either a flat surface 
or another convex surface. A tight seating is thereby much 
more easily obtained than by using two flat surface contacts. 

One of the difficulties experienced with two-hose type cut- 
ting torches is the back pressure of the acetylene into the 
oxygen hose. Under certain conditions this results in the 
oxygen hose becoming filled with mixed gases w^hich ignite at 
tlie tip and a more or less serious flashback into the oxygen 
hose is unavoidable. 

The Torchweld back-pressure valve is claimed to prevent 
the acetylene from entering the oxygen hose, since a certain 
pressure on the oxygen is necessary in order to open this valve. 



94 



GAS TORCH AND THERMIT WELDING 



and as the acetylene pressure also tends to close the valve 
still tighter. 

Details of the construction of this torch are shown in 
Fig. 62A. 

CUTTING UNDER WATER WITH A GAS TORCH 

A number of torches have been developed for cutting under 
water. One of these has been successfully used at the Puget 
Sound Navy Yard, Washington State, for some time, and was 
made by putting a special hood over the tip of a regular 




Fig. 63. — Underwater Cutting Torch. A cutting oxygen at 65 lb. pressure ; 
B, preheating oxygen; C, acetylene 24 lb. pressure; D, compressed 
air at 100 lb. pressure. 

Davis-Bournonville cutting torch as shown in Fig. 63. This 
hood is pressed against the metal to be cut, and air at 100 lb. 
pressure forces back the water and protects the flame. An 
electrical device is used to light the torch under water. 

In one case a cut was made 22 ft. under water by a diver, 
who cut out a piece 19 in. in circumference in -J in. ship plate 
and rose to the surface in 6 min. Six in. per min. was the 
rate cut on plate 1 in. thick. It is claimed that this torch 
will cut down to 200 ft. under water. 



CHAPTER VII 

GAS-PRESSURE REGULATORS AND WORKING 
ASSEMBLIES 

►Since the gas pressure required in a welding or cutting 
torch is normally considerably less than that of a generator 
or storage cylinder, some form of pressure reducer or regu- 
lator must be used between a torch and the source of gas 
supply. The regulator used must not only reduce the pressures 
to working amounts, but must keep the gases supplied to the 
torch at as constant a pressure as possible regardless of the 
variation in the pressures at the sources of supply. This will 
be understood when it is shown that, for example, oxygen 
at 1800 and acetylene at 225 lb. pressure per sq.in., taken from 
cylinders, must be mixed in a Davis-Bournonville positive- 
pressure torch at approximate, pressures of 14 and 6 lb. re- 
spectively, when welding steel plate ^ in. thick. The pressure 
in the cylinders will constantly decrease as the gases are used, 
but in order to keep a correct neutral welding flame the gases 
must be supplied to the mixing chamber of the torch at the 
approximate pressures of 14 and 6 lb., and keep close enough to 
these figures for long periods of time to produce the desired 
flame without continual adjusting of the valves. The required 
working pressures are determined by the thickness of the 
metal being operated upon, the make of torch, and the size of 
tip being used, as tables already given indicate, but the prin- 
ciple remains the same in any case. 

Oxweld Oxygen Regnlators and Gages. — The gas-pressure 
regulators used on welding and cutting apparatus are prac- 
tically all made on the same general principle and vary only 
in minor details of construction. An Oxweld oxygen regulator 
shown in Fig. 64 will serve to illustrate the construction in 
general. The principal parts of a regulator of this kind are 
the body proper, regulating or shut-off valve, diaphragm, 

95 



96 



GAS TORCH AND THERMIT WELDING 



pressure-adjusting spring and pressure-indicating gages. As 
a general rule all regulators have two pressure-indicating 
gages, one on the intake or high-pressure line, and one on the 
outlet, or low-pressure line. The gage, however, on the low- 
pressure acetylene line is sometimes omitted when using a low- 
pressure, or injector, torch on account of the low pressure at 
which the acetylene is used. 

In the illustration given, a dust or protecting plug is shown 
screwed into the connecting nut on the intake tube. This is 




Fig. 64. — Details of Oxweld Oxygen -Pressure Regulator. 

of course removed vvdien attaching the regulator to the supply 
pipe or valve. The arrows indicate the flow of tlie gas when 
free to move from the intake to the outlet. Following these 
arrows it will be seen the gas enters the intake and flows into 
the vertical passage A where it goes upward to the high-pres- 
sure gage B, which indicates the pressure of the supply line. 
The gas also flows downward in the same passage until it 
reaches the monel-metal nozzle of the regulating valve at C. 
ir tlie screw D is turned to the left far enougli to prevent 
spi'ing E from forcing the diaphragm F inward against the 
sliding sleeve, then spring G will keep the seat H solidly 



GAS-PRESSURE REGULATORS 97 

against tlie nozzle C and no gas will enter the body of the 
regulator beyond the passage A. However, if the screw D 
has been run inward far enough to put a tension on spring 
E the diaphragm F will be forced inward and the regulating 
valve will be held open. Gas will then flow into the diaphragm 
chamber / until the pressure of the gas against the diaphragm 
overcomes the pressure of spring E. This allows spring G 
to close the regulator valve and stop the flow of gas. The 
flow is not usually actually stopped when the torch is in use, 
since the flow of gas and the pressure of the spring E will 
be so balanced as to allow just enough gas to enter to keep 
the pressure practically constant in the outlet line. The farther 
the screw D is run in the more tension is put on the spring E 
and the diaphragm F, and consequently the higher will be the 
gas pressure in the outlet line to the torch. From this it will 
be seen that any desired pressure within the capacity of the 
regulator can be obtained, and maintained, in the outlet to 
the torch by simply adjusting the screw D. The diaphragm 
used on a regulator of this kind may be made of reinforced 
sheet rubber, phosphor bronze or other composition metal that 
will not corrode or break easily. 

The regulators used for other gases differ but little from 
those used for acetylene or oxygen, and often the same regu- 
lators may be used provided the pressures required are within 
the range of the regulator in question. An oxygen regulator 
for cutting work should be built heavier and deliver a larger 
amount of gas than one used for welding on account of the 
higher pressure required and greater gas consumption. In 
using acetylene from a pressure generator it is good practice 
to have an acetylene line regulator as well as one for each 
operator's torch line. 

The Oxweld oxygen gages used when welding are made 
to register from to 2700 lb. per sq.in. on the high pressure 
side and from to 60 lb. per sq.in. on the low-pressure side, 
as shown in Fig. 65. It will be seen, by examination, that the 
outer scale on the high-pressure gage shows the pressure in 
pounds and the inner scale indicates the percentage of gas in 
the cylinder. That is, for example, if the gage hand points to 
600 lb. there would be approximately 35 cu.ft. of oxygen left 
in the cylinder, providing a 100-cu.ft. cylinder was being used. 



98 



GAS TORCH AND THERMIT WELDING 



If it was a 200-eu.ft. fylindor the amount loft would be ap- 
proximately 70 cu.ft. As has been pointed out elsewhere, 
these figures cannot be taken as showing the exact amount of 
gas in the cylinder except under certain conditions, but they 
are sufficiently accurate for all ordinary purposes. 

For cutting purposes the Oxweld oxygen regulator shown 
in Fig. 66, is fitted with the same gage on the high-pressure 




Fig. 65. — Oxweld Oxygen Welding Eegulator. 

side as for welding, but on the low-pressure side the gage 
registers up to 200 lb. per sq.in. Their acetylene regulator 
is only supplied with a 350-lb. gage on the high-pressure side, 
as shown in Fig. 67. This is because of the fact that the 
Oxweld torches use acetylene at about 1-lb. pressure at all 
times. However, if required, two gages may be used as in all 
other makes. 



GAS-PRESSURE REGULATORS 



99 



Other Reg'ulators and Gages. — A Davis-Bonrnonville oxygen 
regulatoi- with gages is sliown in Fig. 68. This indicates from 
to 3000 lb. per sq.in. on the high-pressure side and up to 
400 lb. on the low-pressure side. On the dial of the high- 
pressure gage are three rows of figures. The outer row shows 
the pressure per sq.in. ; the middle row, the cubic feet of 
contents for both 100- and 200-ft. cylinders; the inner row 
indicates the cubic feet of contents for 250-cu.ft. cylinders at 




Fig. 66. — Oxweld Oxygen Cutting Regulator. 

various pressures. Details of a regulator used for acetylene are 
shown in Fig. 69. This is practically the same in construction 
as the oxygen regulator. The numbers shown are list numbers 
of the parts, and are very convenient for ordering broken or 
damaged parts at any time. The regulator acetylene gages 
register up to 400 lb. on the high-pressure side and up to 
300 lb. on the low-pressure side. 

An oxygen regulator made by the General Welding and 
Equipment Co., attached to a cylinder is shown in Fig. 70. 



100 



GAS TORCH AND THERMIT WELDING 



At the right and almost opposite from where tlie regulator 
is attached, is a projection which is a fusible blow-off plug 
i-equired on all cylinders by the Interstate Commerce Com- 
mission, to provide for the escape of the gas in case the cylinder 
should be overheated and the pressure become so great as to 
be liable to cause an explosion. This illustration clearly shows 
tlie kind of valve that is used on an oxygen cylinder. It is 
completely covered with a metal cap screwed onto the threads 




Fig. 67. — Oxweld Acetylene Regulator. 



snown at the top of the cylinder. The cap protects the valve 
and prevents it being broken off or damaged when the cylinder 
is handled or shipped. In using gas cylinders under working 
conditions it is advisable to have them placed on a portable 
truck made for the purpose, or else fastened in some way so 
that they cannot be tipped over. This will often prevent 
needless damage to the apparatus and sometimes avoid serious 
accidents. It should always be kept in mind that gases under 



GAS-PRESSURE REGULATORS 



101 



fi-oni 225- to 1800-lb. pressure per square inch arc not to be 
trifled with. 

Tank and Hose Colors. — Oxygen cylinders of ditferent con- 
cerns do not have a uniform color, but are usually painted 
gray and green, i-ed, yellow or dark-green. Acetylene cylinders 
are generally painted black and have a plate on them giving 




Fig. 68. — Davis-Bournonville Oxygen Eegulator. 

the quantity of gas the tank contains. Practice also varies 
as to the color of hose used to connect to the torches. Common 
colors arc black hose for acetylene and red hose for oxygen, 
although sometimes oxygen hose is black and the acetylene 
red. In making all hose or valve connections, they must be 
carefully bloAvn out to remove dust or any foreign substance. 
This is especially important on new hose which is almost sure 



102 



GAS TORCH AND THERMIT WELDING 



to contain considerable bloom left from the vulcanizing. In 
addition to their specific color, acetylene cylinder valves are 
often threaded left hand, as a safeguard against making the 
wrong connections. 



2426 A 




'^m^i^zam^^ ^g^jijgg 



14 1-:'%V <^f^"=^ F 







I52C 



2919 

29'23,-'Vl 1'^ 
2926^ "U_ f{ 
2916 -- -il_ 
Fig. 69. — Details of Davis-Bouruonville Acetylene-Pressure Eegiilator. 



Id making oxygen connections it must be remembered that 
under no circumstances should oil or grease be used on the 
oxygen regulator or cylinder valve. This is highly important 



GAS-PRESSURE REGULAT()i;S 



103 



as oxygen under pressure eoining in eontael with oil or gi'ease 
causes spontaneous eombustion whieh might easily result in 




Fig. 70.— Regulator Attached to a Gas-Cylinder Valve. 




Fig. 71. — Regulator and Cylinder-Couiioction Adapters 

a serious aecident. If a lubricant of any kind is needed a 
little glycerine may be used. 

Regulator Adapters. — No make of regulator is so made as 



104 GAS TORCH AND IHEi^MIT WELDIXr. 

to be regularly interehangeahle with all makes of gas cylinders, 
since the sizes and threads used on diffei'cnt makes of cylinder 
connections vary considerably. Foi- this reason adapters must 
be used in many cases. Some of these are shown in Fig, 71. 
Care should therefore be taken to make sure that the regulator 
will fit the cylinder connections properly, or that the right 
adapter is used. If a regulator connection or an adapter does 
not start readily, it should not be forced as it is probably the 
wi"ong diameter or the thread may be of the opposite kind — 
that is right- or left-hand. Also be sure that an adapter with 
a round or conical seat is not used on a tlat seat, nor a round 
seat on a conical one or one not nmde for it. Adapters are 
made of soft brass and careless handling will cause a leaky 
joint. In ordering adapters the make of regulator used should 
he specifically stated, and also tlie make of cylinder on which 
it is to be used, as well as whether it is for oxygen, acetylene, 
h.ydrogen or other gas. 

Connecting Up and Lighting the Torch. — In order to make 
perfectly clear to the reader how to connect up a welding 
apparatus for the first time, an Imperial welding outfit is 
shown in Fig. 72. Fii'st I'cmove the protecting cap from the 
oxygen cylinder, and then open valve A very slightly. This 
is to blow out any dust and to insure the free working of the 
valve after the regulator is attached, which otherwise might 
be injured by the sudden rush of gas into it. In doing this, 
stand on the side opposite from the opening so that the gas 
will blow away from yoii. Always keep this in mind when 
blowing out the valve on any cylinder. Now take the regulator 
and turn the handle B to the left until it turns freely, so as 
to be clear of the diaphragm. Next make sure the connection 
at C is clean and free from dii't and fits properly or has the 
right adapter, then screw it up using judgment with the 
wrench so as not to break anything. With the valve at D 
closed, slowly open the valve A as far as it will go, using some 
force with the hand to insure that it is really backed up 
against the gland solidly. This is to aid in preventing the 
high-pressure oxygen from escaping around the valve stem. 
AVhen the valve is fully opened, the gage E will indicate the 
cylinder pressure which on a new one will be close to 1800 
lb. Now put on the oxygen hose at F and then turn the 



GAS-PRESSURE REGULATORS 



105 



handle B to the right until about 5 lb. are registered on gage G. 
Then open valve to D so as to blow any dirt or bloom out of the 
hose. The valve D is then closed and the hose connected to the 
torch at H. The valve / on the torch may now be closed, the 
valve D opened, and the handle B screwed in until the gage 
G registers the proper pressure for the proposed welding job. 




Fig. 72. — Imperial Welding Outfit Connected to Tanks. 

as indicated in the pressure table for the make of torch being 
used. The various connections should then be carefully gone 
over with soapy water to test for leaks. Never use a flame 
on the oxygen or any other gas tank even though oxygen alone 
is not inflammable. Assuming that the proper tip has been 
placed in the torch for the thickness of metal to be welded, 
the torch valve I may now be opened fully and the handle 



106 GAS TORCH AND THERMIT WELDING 

screwed in until the gage G registers about 2 lb. over the 
pressure given in the tabk'. This is to allow for the variation 
in cylinder pressure as the gas is used. The torch valve / is 
next closed, and it is also well to close the valve i> as a safe- 
guard before attaching the acetylene hose. 

The acetylene regulator and tank are now connected up 
in exactly the same way, except that the acetylene tank valve 
/, must be only opened one full turn. (On one make of 
cylinder the dii-ections say two tui'ns, so the operator should 
read the dii'ections on the tanlv carefully.) The hose is con- 
nected at K and blown out to remove any dirt, care being 
taken that no flame is near. It is then connected to the torch 
at L, and tests are made for leaks as before with the valve M 
open and the torch valve N closed. The torch valve N is next 
slightly opened and the issuing gas lighted. The valve is 
then fully opened, and if the gage shows any appreciable 
drop, the handle P should be turned until the gage registers 
about 2 lb. above th(> amount shown by the table. The resulting 
flame from the Inirning acetylene will be long, white, smoky, 
and of comparatively low temperature. The torch valve N 
may then be manipulated until ihc pressure l^lows the flame 
from Vig to ^/4 in. away from the tip, the distance depending 
on the size of the tip being used. This can only be judged 
properly by experience. The oxygen may now be turned on 
slowly. The flame will gi-adually i-eduee in size, the outer end 
or envelope becoming less luminous and the part near the torch 
tip, known as the cone, assuming a clear outline without any 
ragged edges. Wlien this is obtained, turn off the oxygen 
slowly until a shadowy point shows from the cone. Then with 
extreme care turn on the oxygen again until this shadowy 
point just disappears. This is the so-called neutral flame, and 
is neither oxidizing nor carbonizing. 

From time to time, while at work, the operator should test 
the flame as just outlined, as a slight excess of oxygen pressure 
will not readily show in the flame and can only be detected 
by this method. It will be found in practice, as a rule after 
the pressures have been set on the gages, that all regulation 
necessary for the smaller sizes of tips may be made with the 
torch valve, but that on the regular sizes it is often advisable 
to readjust at the regulators. It will be well to repeat here, 



c.As-ri;Kssum'; rkculators 



107 



for the l)enc'(it of the beginner, that all indicated table pressures 
are only approximate and good only for the make of torch 
mentioned in connection with them. 

Characteristics of the Oxy-Acetylene Welding Flame. — 
The chart shown in Fig. 73 will serve to illustrate the looks 
of the oxy-acetylcnc flame as far as it is possible to do on 
paper: A shows acetylene turned on with sufficient pressure, 
so that it blows away from the tip. This space depends upon 
the size of tip being used. B shows oxygen partly turned 
on, united with the acetylene. The flame has hcgun to assume 
two different shapes and two different colors. The center 




A B 

Fig. 7'.i. — Characteristics of the Oxy-Acetylene Welding Flame. 

flame is white and is shaped somewhat like a rosebud. Not 
enough oxygen has yet been given the acetylene and the flame 
is called carbonizing. Such a flame will leave the metal brittle 
and hard. G is the neutral welding flame. The rosebud cone 
of th(! upper figure has become blunt, with no ragged edges 
and of a beautiful blue-white color. D is an oxidizing flame — 
ruinous to welding. This is obtained by turning on too much 
oxygen and the cone has become shorter, of a darker, dirtier 
blue, and is more pointed. Tliis view is exaggerated. The 
utmost care is necessary to guard against this flame. Even a 
slight excess of oxygen is detrimental, as it will "burn" the 
metal. 

To stop work temporarily, first close the oxygen valve in 



108 GAS TORCH AND THERMIT WELDING 

the torch and then the acetylene valve. To stop work per- 
manently, first close the torch valves in the order just given, 
then screw back both regulator handles until they are free 
of the diaphragms. Then shut off the tank valves tightly. 

In case of a flashback, always close the oxygen valve in- 
stantly, then the acetylene valve, after which the torch head 
may be cooled in a bucket of water. It should always be kept 
in mind never to turji on the gas at the cylinder with the 
regulating screw tight, as this puts spring tension on the 
diaphragm and allows the gas from the cylinder to enter the 
body of the regulator very suddenly (because the plunger of 
the valve is away from the seat) and as the sudden pressure 
strikes the diaphragm, the plunger is thrown violently against 
the seat, often causing the seat to become cracked or broken. 

With the motor of an automobile racing, you wouldn't 
throw the gears in mesh for high speed direct from neutral 
and attempt to start away from the curb — not if you wanted 
to keep your automobile very long — yet turning on the oxygen 
with the spring tension on the regulator has about the same 
effect on the regulator. 

Bear in mind that the regulator is a steadying device — that 
the diaphragm is the balance between the higli pressure of 
the cylinder gas and the spring tension and that at all times 
the movement of this diaphragm should be slow — never violent. 

The low-pressure gage is a positive index of regulator 
trouble. If you are operating, say at 15 lb., and after shutting 
off the valve on the torch, the hand on the dial keeps moving 
to 25 or 30 or 40 lb. without stopping, it means that the seat 
is damaged — that the high pressure of the cylinder is leaking 
past the plunger of the valve and the regulator should be 
immediately sent back to the factory for repairs. Only by 
violating some of the rules previously given would you be 
likely to damage this seat ; but once damaged, it should be 
immediately repaired. 

It will be noticed that two acetylene tanks arc shown in 
Fig. 72. These represent the two types in common use. The 
one in the middle is the type furnished by both the Air Re- 
duction Sales Co. and the Commercial Acetylene Co., while 
the tank at the left is furnished by the Prest-0-Lite Co. In 
the first named the regulator stands out at right angles, and 



GAS-PRESSURE REGULATORS 



109 



in the other it stands up as shown. The valve in the Prcst- 
0-Lite cylinder differs considerably from the others as will 
be seen in Fig. 74. In this illustration the valve is shown at 
A, the valve wrench at B, the packing nut of the valve at C, 
and the union nut by which tlie regulator is attached, at 
D. E is the high-pressure gage, F the low-pressure gage, G, 
the regulator, H the pressure-adjusting handle, 1 the outlet and 
J the hose nipple. 

Lighting the Oxweld Low-Pressure Torch. — The directions 
given by the Oxweld company for the lighting of their low- 
pressure or injector torches, differ slightly from the foregoing. 




Fig. 74, — Prest-0-Lite Acetylene-Regulator Assembly. 



so they will be quoted here, starting from where the gases 
have been turned into the high-pressure sides of the regulators, 
which is the same as already outlined : 

First, connect the oxygen hose from the oxygen regulator 
to the hose connection on the torch marked oxygen. Likewise 
connect the acetylene hose to the torch valve marked acety- 
lene. Then select the proper welding head or tip that is to 
be used according to the chart or table furnished, and screw 
it carefully into the torch. Turn on the oxygen by means of 
the handscrew of the oxygen regulator until the pressure on 
the small gage is as given on the chart. Be sure that when 
this is done the oxygen valve on the torch is open. Then close 



no GAS TORCH AND THERMIT WELDING 

tliis valve. Open the acetylene valve on tlie toi-cli. Then turn 
the liandscrew on the acetylene regulator to tlie riglit until 
acetylene is passing through the torch. Then close the acety- 
lene valve on the torch. 

,The apparatus is now ready for use, and the gases are 
further regulated when necessary by adjusting the valves on 
the torch itself. Open the acetylene valve entirely. Open the 
oxygen valve slightly. Then light the gases. After lighting 
the gases, open the oxygen valve wide ; adjust the flame by 
turning the acetylene valve to the right until a neutral flame 
is produced. 

"When the job is finished and you want to shut off the torch 
for a short time, release or turn the handscrew on both oxygen 
and acetylene regulators to the left until the flame on the torch 
goes out. Then close the torch valves. When work is completed 
for the day and the apparatus is to be put away, first close 
the acetylene valve, then the oxygen valve of the torch. Then 
turn off the valves on hofli cylinders. Then open the valves 
on the torches until all the gas in the regulators and hose 
passes out of the torch into the air. Then turn the handscrew 
of both regulators to the left until loose. Then disconnect 
the oxygen and acetylene regulators from the cylinders. Each 
regulator has a dust plug which is to be put on its cylinder 
connection during all the time the regulators are not con- 
nected to the cylinders. 

Place the regulators and torches with wrenches, goggles, 
heads, and tips in their proper place so that they will be 
safe and protected from dust, dirt, and rough handling. Roll 
up the hose and put it in the case or tool box where it belongs. 

Chemistry of the Oxy-Acetylene Flame. — According to the 
Prest-0-Lite company, the chemistry of the oxy-acetylene 
flame is as follows: Acetylene (CoH.,) is composed of carbon 
(C) and hydrogen (H). On combustion, the carbon combines 
with oxygen to form carbon dioxide (COo) and the hydrogen 
combines with oxygen to form water vapor (HoO). This takes 
place in the following manner: 

When the gases issue from the torch into the welding flame, 
the acetylene immediately dissociates; in other words, it siplifa 
up into carbon find hydrogen which in combination with oxygen 
form respectively carbon dioxide and water vapor. In con- 



GAS-PRESSURE REGULATORS 



HI 



sequence of the high flame temperature (6300 deg. F.) the 
water vapor formed by this primary combustion is immediately 
dissociated into hydrogen and oxygen. The oxygen assists in 
the burning of the carbon while the hydrogen (which can only 
combine with oxygen at a temperature below 4000 deg. F.) 
passes away from the high-temperature zone and combines 
with the oxygen of the atmosphere at the outer blue part of 




Fig. 75.— Imperial Three-Way Gas Outfit. 

the flame, where the temperature is sufficiently low to permit 
it. The result of this is that the inner or welding cone of the 
flame is protected by a shield of free hydrogen which prevents 
loss of heat and also tends to protect the weld from oxida- 
tion. The temperature of the oxy-acetylene flame is approxi- 
mately 6300 deg. F., at the hottest part of the flame, which is 
the tip of the inner white cone. The effect of this tremendous 
heat at the point of treatment is to bring the metal very 



112 GAS TORCH AND THERMIT WELDING 

rapidly to a molten state so that it flows together and mixes 
thoroughly with the proper quantity of metal added by the 
operator. 

The molten mass thus formed does not merely cement two 
pieces of metal together — it fuses them into one uniform mass. 

Characteristics of Other Gas Flames. — The way an Imperial 
three-way outfit is connected up is shown in Fig. 75. The 
procedure is along the same lines as outlined for the oxy- 
acetylene work. This combination of oxygen, acetylene and 
hydrogen gives a more visible flame and a sharper cone than 
oxy-hydrogen alone does. Only a small percentage of acetylene 
is necessary to give the sharper cone but the flame retains 
the clearness, beauty and good qualities of the oxy-hydrogen 
flame. The percentage of acetylene may be varied according 
to the thickness and character of the metal being welded, so 
that the degree of heat and amount of carbon can thereby 
be regulated to meet different conditions. The approximate 
pressures to be used for the three gases for average w^ork, 
will be found in a previously given table. The combination 
will produce a heat of about 5000 cleg. F. 

The oxy-hydrogen flame will produce a much softer weld 
than oxy-acetylene if properly used, but its lower heat and 
the fact that the cone is not concentrated in a sharjD needle 
point, which allows the heat to radiate more, are drawbacks 
wdien heavy welding is attempted. The low visibility of the 
oxy-hydrogen flame also makes it difficult to regulate properly, 
and an operator requires considerable experience before he 
can become proflcient in its use. As has been already men- 
tioned, however, its long flame makes it very desirable to use 
for the preheating flame in a cutting torch, especially on 
heavy, thick work. In welding with the oxy-hydrogen flame, 
the torch has to be held farther away from the work than 
with the oxy-acetylene torch on account of the longer and 
less concentrated flame. When a black spot appears in the 
weld it shows that the torch is being held too close. 

The Oxy-Hydrogen Flame. — The characteristics of the oxy- 
hydrogen flame are shown in Fig. 76. In this illustration, 
v/hich is as clear as a flame can be represented on paper, the 
different flames are outlined as follows : E shows the hydro- 
gen turned on Avith sufficient pressure so that it blows away 



GAS-PRESSURE REGULATORS 



113 



from tlio end of tlic tip. The distance will vary from about 
\/jy to V4 ii^- according to the size of tip and pressures used. 
F shows the oxygen turned on. A narrow, light-blue streak 
appears in the center of the hydrogen mantle. This is the 
desired neutral flame. G is an oxidizing flame that will burn 
the metal. The oxygen valve should be gradually closed until 
the excess of oxygen disappears. 

Where hydrogen and compressed air are used as is done in 
preheating work, light welding, or lead burning, the flame 
closely resembles that of the oxy-hydrogen flame. The appear- 



Jb/ue " 



Fig. 76. — Characteristics of the Oxy-Hydrogen Flame. 



ance of the hydrogen-air flame is indicated in Fig. 77. E 
shows the hydrogen turned on with pressure enough to blow 
the flame away from the tip, the distance being about the 
same as already given. I shows the compressed air turned on 
and a dark streak of mixed air and hydrogen appears in the 
center. This is the neutral flame. / is the oxidizing flame. 

In general the air pressure used for this flame is close to 
that where oxygen is used. 

The Oxy-IUuminating Gas Flame. — The flame produced by 
mixing oxygen and coal gas, or natural gas, is suitable only 
for lead burning, preheating, very light steel welding, light 
cast-iron welding, or the welding of light brass or aluminum. 



114 



GAS TORCH AND THERMIT WELDING 



The cliaiactei'lstich; are shown in Fig. 78. K shows the gas 
turned on full force enough to slightly blow the yellow flame 



DarA- 



FiG. 77. — Characteristics of the Hyilrogen-Compressed-Air Flame. 



Purple - - 



Blue- 



FlG. 78. — Characteristics of the Oxygen Illuminating Gas Flame. 

away from the tip. L is the neutral flame produced by turn- 
ing on the oxygen. The cone is narrow and about \ in. long, 
of a beautiful purple color in a pure-blue outer mantle. M 



GAS-PRESSURE REGULATORS 115 

shows too much oxygen. The cone has turned a reddish color. 
The oxygen must be decreased until the sharp purple-colored 
cone appears. In using oxygen and illuminating gas, a water 
seal should be used on the gas line to assist in purifying the 
gas and to prevent the entrance of .any flame, or Oxygen which 
might form an explosive mixture. 

Where acetylene and compressed air are used, as is some- 
times done for certain preheating or welding jobs, the flame 
characteristics closely resemble the oxy-acetylene flame. 

In order to obtain the best results, special tips should be 
used in the torch for the different gas combinations described. 
These can usually be promptly supplied by the makers of any 
of the torches on the market. 



CHAPTER VIII 
GAS-TORCH WELDING AND CUTTING OUTFITS 

Cutting torches are lighted in the same way as are the 
welding torches. In most cases, however, the oxygen pressure 
to the preheating flame has to be several pounds higher, on 
account of the drop after the cutting jet is turned on. Tlie 
apparatus used for cutting is also set up in the same way as 
for welding, as will be seen from the typical Oxweld cylinder 
outfit shown in Fig. 79. 

Where large amounts of oxygen are used for cutting or 
welding, it is well to have a centralized source of supply so 
arranged that the flow of oxygen need not be interrupted at 
any time, and will be ample for all demands. For this pur- 
I^ose, the Oxweld company has designed the oxygen cylinder 
manifold shown in Fig. 80. Oxygen from this manifold 
may be piped anywhere in a plant exactly the same as the 
acetylene is. It eliminates the enormous amount of handling 
necessary in supplying full cylinders and removing the 
empty ones from each individual station. The manifolds are 
so arranged that each half operates independently, making 
it possible to provide an uninterrupted supply of oxygen. 
If desired, both halves may be operated in unison. These 
manifolds are made in four sizes to accommodate, 6, 10, 20 
and 30 cylinders respectively. Each manifold will handle 
cylinders of either 100- or 200-cu.ft. capacity without any 
additional change or adjustment. They have two constant 
pressure regulators, one of which is for relief service. 

Acetylene cylinder couplers or manifolds are used for the 
same reason as are those for oxygen. A number of Prest-0- 
Lite acetylene cylinders coupled together is shown in Fig. 81. 
These are valuable where large-sized torch tips are used 
more or less continuouslv, since the capacity of the cylinders 
supplying acetylene should be at least seven times the hourly 

116 



GAS-TOKCH WELDING AND CUTTING OUTFITS 



117 



consumption. Where the hourly requirements are from 61 
to 75 eu.ft. of acetylene, 5-WC or 2-WK size cylinders should 
be used. 

Complete Working Outfits. — A welding or cutting outfit 
may consist of the bare essentials, or be so complete as to 



OXYGEN REOULKTOR 



Oxygen Tank Valve 
Connection ^^ut 
Safety VaWe 

ACETYLENE REGULATOR 

Tank or High- 
-Pressure Gage 

Connecting Nut' 

Adapter 
Safety Valve-- 



Tank or High- 
Pressure Gage 
--Low-Pressure 
Gage 
"■-Handle 

Outlet Connection 

--Cutting 
Nozzle 

il^- -Torch 
Head 




TORCH 
Cutting ValveJ 
, -Lever 



-Handle 

, Oxygen 
"Valve 

".Oxygen Hose 
Connection 



Acetylene Hose-' 
Fig. 79 Typical Oxy-Acetylene Cutting Unit. 

include everything that will be needed to care for any job 
that will come along. The outfits may also be of either the 
stationary or the portable type, or a combination of the two. 
If of the stationary type, there will naturally be included 
many things such as holding jigs and fixtures which do not 



118 



GAS TORCH AND THERMIT WELDING 




Fig. 80. — Oxweld Oxygen-Cylinder Manifolds. 



' -ARRESTER- 



r^ 



*-h\ 



■l — 



%..M^m'^^ 



Fig. 81. — Prest-0-Lite Acetylene-Cylinder Manifolds. 



GAS-TORCH WELDING AND CUTTING OUTFITS 119 

ordinarily belong to the strictly portable type. Two typical 
lists of parts and material for the ordinary run of work, where 
gas cylinders are used, are here given. These lists are taken 
from the catalogue of the K-G Welding and Cutting Co., 
New York. 

OX\'-ACETYLENE CUTTING UnIT 

1 cutting torch, standard size, witli four interchangeable tips of 

graduated sizes. 
1 high-pressure oxygen regulator, with 3000-lb. gage for cylinder 

pressure, 300-lb. gage for working pressure and one reducing valve 

with connection for hose coupling and needle valve. 
1 acetylene-pressure regulator with 400-lb. gage for cylinder pressure, 

60-lb. gage for working pressure and one reducing valve with 

connection for hose coupling and needle valve. 
25 ft. high-pressure, copper-covered oxygen hose. 
25 ft. steel-covered gas hose. 
1 pair colored goggles for operator. 

1 pair fireproof gloves. 

2 wrenches and flint lighter, instructions, etc. 
1 leather instruction and memorandum book. 

OXY-ACETYLENE WELDING UNIT 

1 welding torch, standard size, complete with eight interchangeable 
tips of graduated sizes. 

1 low-pressure oxygen regulator, with 3000-lb. gage for cylinder pres- 
sure, 60-lb. gage for working pressure and one reducing valve 
with connection for hose coupling and needle valve. 

1 acetylene-pressure regulator with 400-lb. gage for cylinder pressure, 
60-lb. gage for working pressure, and one reducing valve with 
connection for hose coupling and needle valve. 
25 ft. red corrugated-rubber oxygen hose. 
25 ft. black corrugated-rubber gas hose. 

1 pair colored goggles for operator. 

1 pair fireproof gloves. 

2 wrenches, 1 flint lighter, instructions, etc. 
10 lb. cast-iron rods. 

10 lb. Norway iron for welding. 
2 lb. aluminum rods. 
1 lb. cast-iron flux. 
I lb. aluminum flux. 

It, of course, is not necessary for a user to purchase two 
complete units if his work does not warrant it, as these may 
be judiciously combined. For instance, the welding unit may 
be used for either welding or cutting if a cutting torch and 



120 GAS TORCH AND THERMIT WELDING 

a liigli-pressuro oxygen regulator are added. It is very con- 
venient where portable apparatus is used to a considerable 
extent over an extended territory, to have a suitable carrying 
case for the smaller parts. This may consist of a chest attached 
to the cylinder or portable truck, or of a hand case, such as 
shown in Fig. 82. This ease and outfit is sold by the Air 
Reduction Sales Co., New York, and holds everything neces- 
sary for immediate attachment to the cylinders and starting 
to work. 

It has been previously mentioned that it is not advisable 





Fig. 82. — Carrying Case for Welding and Cutting Outfit. 

to place gas cylinders so tliat tliey may be knocked over. 
If they have to be stood up near the work, it is best to chain 
them to a post or brace them up in some way. A portable 
tr-uck is, of course, the best of all where outfit must be moved 
about. Such a hand truck has already been shown. Prac- 
tically every firm making gas-torch supplies sells a similar one. 
A very impoi'tant part of any gas-torch outfit is a pair 
of suitable glasses or goggles. These should not be merely 
dark glasses, but the lens should be made expressly for work 
of this kind. Cheap glasses are dear at any price, as the result 
may be ruined eyesight from the intense glare of the hot metal 



GAS-TORCH WELDING AND CUTTING OUTFITS 121 

or from injurious rays. The glasses may be of either the 
spectacle or the goggle form, but the lens should be the same 
in either case. Glasses may be obtained from practically any 
of the firms mentioned in the various descriptions. The goggle 
form of glasses has the advantage over those of the spectacle 
type in that they will better protect tlie eyes from flying or 
ghmcing particles of hot metal or sparks. It is well to have 
tlic colored lens protected by clear glass. A pair of goggles 
is shown in Fig. 83. These are of a very satisfactory form. 
They are light and all parts that come in contact with the skin 
sliould be made of fiber, metal, or something that is sanitary 
and easily sterilized. The guards may be made of aluminum 
screen or fiber. Never on any account use goggles with guards 




Fig. 83.— Goggles for Gas-Toreh Work. 

made of celluloid. If the glasses used can be employed for 
long periods of time without the eyes feeling ''dazzled," or 
if they can be removed without white spots appearing before 
the eyes, then they are all riglit. Otherwise get others that 
are better fitted for the work and your eyes.. A darker lens 
is usually used for welding than for cutting and sometimes it 
is advisable to use different glasses for different metals. These 
will enable the operator to see more clearly when the glare 
is not so intense. 

Fire-fighters often need to cut through steel or iron win- 
dow bars, shutters, steel plates or sheathing, in order to rescue 
imprisoned persons or to get at a fire advantageously. For 
this purpose the Davis-Bournonville Co. supplies a very com- 
pact apparatus, shown in Fig. 84. The metal case is 6^ in. 



122 



GAS TORCH AND THERMIT WELDING 



wide, 14 in. deep and 50 in. high. It contains a 40-cu.ft. 
cylinder of acetylene, a 50-cu.ft. cylinder of oxygen, and a 
complete cutting unit with extra length of hose. Handles on 
each side of the case provide means for easy carrying by two 




Fig. 84. — Emergency-Cutting Outfit. 

men, and these handles placed as shown, when in use, insure 
stability. The complete outfit weighs 125 lb. 

A complete two-station welding and cutting outfit of the 
stationary type, using an acetylene generator and oxygen 



GAS-TORCH WELDING AND CUTTING OUTFITS 



123 



'JSi 




be 



O 







o 



o 

I 






124 



GAS TORCH AND THERMIT WELDING 



cylinders, is shown in Fig. 85. This can be extended to include 
any number of individual stations, according to the size of 
the generator employed. It is advisable to place the acetylene 
generator in a separate room or building. The oxygen cylinders 
and regulators arc placed within easy reach of the workers. 
Back-Pressure Valves. — Hydraulic back-pressure valves 




Fig. 86. — Oxweld Low-Pressure Hydraulic Back-Pressure Valve. 



should always be connected to the individual acetylene pipes, 
as shown, to avoid the danger of a flashback or an explosive 
mixture entering the acetylene line. An Oxweld low-pressure 
back-pressure valve is shown in Fig. 86. In some quarters it 
is thought that such a valve is not needed where positive- 
pressure torches are used, but this is not true, as the danger 



GAS-TORCH WELDING AND CUTTING OUTFITS 125 

is always present when the oxygen pressure is greater than 
that of the acetylene or which, through accident, may become 
greater. An obstruction in the nozzle of the torch, or clogging 
of certain passages is apt to force the oxygen into the acety- 
lene line. There are also other conditions which may cause 
a serious accident. While mechanical valves may help, they 
are not so reliable as hydraulic valves and should not be used 
on shop lines. In the Valve shown, the acetylene enters at A and 
bubbles out at B where it rises to the surface of the water 
seal, and normally goes out of the hose valve C. The depth 
of the water through which the acetylene bubbles is sufficient 
to cover the tube leading to the outside air. If there is a 
backward flow of oxygen, the pressure exerted on the surface 
of tlic water lowers its level, causing it to rise in the tube 
open to the air, and if continued, forces it out of the tube, 
thus opening a clear passage for the oxygen to the outside 
air at D. The acetylene inlet meanwhile is protected by a seal 
of water. 

To avoid the possibility of blowing the water out of the 
seal, the valve is so designed that in case of a blow-back the 
water automatically flows back to the body of the valve, renewing 
the seal. 

The high-pressure valve of this type is provided with a ball 
check seated under water, which effectually prevents an excess 
pressure from working backward into the generator. It is 
also supplied with a relief valve of ample size to carry off 
any excess pressure which may accumulate in the body of the 
hydraulic valve. 

Both the high-pressure and low-pressurp valves should be 
kept full of water up to the screw plug E which is provided 
to regulate the height of water when filling. 

Lead Burning. — Lead burning is practically the same as any 
other Avelding work, except that the melting point of lead 
(620 deg. F.) calls for a much smaller flame. The same outfits 
intended for lead burning may be used for welding jewelry, 
small metal parts of various kinds, or for brazing work in 
some cases. On account of the torch itself being made small 
and as light as possible, it is customary to have only an oxygen 
valve on it, the gas and oxygen valves being placed in a "bench 
block" placed about midway between the torch and the sources 



126 



GAS TORCH AND THERMIT WELDING 



of supply. For lead burning alone, it is usually advisable to 
use some gas combination giving less heat than oxy-acetylene, 
such as oxy-hydrogen, iiydrogen and compressed air, oxygen 




Fig. 88. — Oxy-Hydrogen Lead-Burning Outfit. 



and illuminating gas, or others. In order to assist the would-be 
user, several typical set-ups, taken from the Imperial Hand- 
book, will be shown. 

An oxy-acetylene combination is shown in Fig. 87. This 



GAS-TORCH WELDING AND CUTTING OUTFITS 



127 



shows the bench block A, screwed to the wall, which in many 
cases is the better way. However, it is well to have this block 
in easy reach of the operator. The oxy-hydrogen set-up is 
very similar, as shown in Fig. 88. 

A hydrogen compressed-air unit is shown in Fig. 89. A 
constant air-pressure regulator is shown attached to the air 
line. In Fig. 90 is shown an oxygen-illuminating gas combina- 
tion. A water seal is used on the gas line as a safeguard and 
to act as a scrubber to some extent. 

A very light outfit, intended for jewelers, dentists, or cx- 




FiG. 89. — Hydrogen and Compressed-Air Outfit. 

perimental laboratory work, is shown in Fig. 91. The bench 
block differs some from the ones just illustrated. The torch 
itself is almost as light and is about the size of a large fountain 
pen. "With the bench block close to the operator, the torch 
valve is not needed. This outfit is made by the Davis-Bournon- 
ville Co. A very convenient feature is the torch-holding clip, 
shown at the top of the bench block. This obviates the neces- 
sity of laying the torch down at any time, with its attendant 
danger of fire. 

A Gas Flow Indicator. — It is often desirable to measure 
the flow of gases used in a welding or cutting torch. For this 
purpose, the Hydrate Engineering Corporation, Buffalo, N. Y., 



128 



GAS TORCH AND THERMIT WELDING 



has produced the Hydrex Flow Indicator shown in Fig. 92. 
In Fig. 93 the principle on which it works is outlined. The 
gas enters the nipple a, as indicated hy the arrow. Thence it 
flows into the chamber c, up through the tube d and out the 
nipple h. As the gas passes into tube d it raises the plunger c. 
The greater the flow of gas the higher will the plunger be 
lifted. The disk / is suspended from plunger e and is visible 
through the gas tube g, so that the flow of gas is indicated 
on a scale calibrated in cubic feet per hour, reduced to normal 




Fig. 90. — Oxygen and Illuminating Gas Outfit. 

conditions for a gas flowing at a definite pressure and a 
definite temperature. 

The gas at the time it is measured, may flow at a known 
pressure and a known temperature, which do not coincide with 
those for which the calibration is prepared. In such a case 
the reading has to be converted into the proper volume, by 
applying those formulas which govern flow of gas through 
orifices. 

These calculations, of course, should not be necessary for 
a conveniently applicable apparatus. The elimination of com- 
putations is accomplished by the use of a chart, which permits 



GAS-TORCH WELDING AND CUTTING OUTFITS 



129 



the conversion of a reading for any pressure and temperature. 
This is practical in tlie laboratory where close observation 
and intelligent interpretation of the chart may be expected. 
For the ordinary shop work it is out of place. 

To make the instrument a practical and convenient shop 
and an all-around test apparatus, it was necessary to simplify 
the determination of the volume passing through the flow in- 




FiG. 91. — Manufacturing Jewelers' and Dentists' Welding Outfit. 



dieator. A pressure gage makes this possible. This pressure 
gage indicates factors instead of pressures in pounds per square 
inch. The reading on the flow indicator scale, multiplied by 
the factor, is the actual volume of gas, reduced to normal 
conditions, passing through the flow indicator. Thus, the sliop 
operator is relieved of all complicated mathematical considera- 
tions and he may concentrate his energies upon his work. 



130 



GAS TORCH AND THERMIT WELDING 



The inflnenoc of the temperature npon the reading is ap- 
proximately 1 per cent for each 10 deg. F. 

The influence of the pressure upon the volume is inverse to 
that of temperature, increasing temperature decreases the den- 
sity of gas, while increasing pressure will increase the density. 




Fig. 92. 




•iG. 93.— Details of Gas Flow 
Indicators. 



On a calibration made for 40 Ihs./in." gage pressure, the 
increase of one pound in pressure compensates for an approxi- 
mate increase of 10 deg. in temperature; and if the calibration 
is for 10 Ibs./in." gage pressure, an increase of | Ib./in.^ 
pressure will compensate for an increase of approximately 
10 deg. F. 



CHAPTER IX 
LEARNING TO WELD WITH A GAS TORCH 

Directions as to how to handle a gas torch and to weld 
are of no use without actual practice — and lots of it. How- 
ever, the v/ould-be welder should have certain definite instruc- 
tions given him before he attempts to do any work. To be- 
come a first-class all-round welder requires long experience, a 
mechanical sense, and a liberal application of brains as a flux 
on every job. Learning to do simple, one-operation weldiug 
jobs, however, is comparatively easy if a competent instructor 
is to be had. If such an instructor is not to be had, the direc- 
tions given here will serve as a foundation upon which a fair 
knowledge of the work may be built. It is easier to learn to 
cut than it is to learn to weld, but as welding is the more im- 
portant of the two the method will be described first. 

It is taken for granted that the welder, following directions 
already given, is familiar with his apparatus, has the correct 
size of tip for the metal to be welded, knows how to light his 
torch and has ample gas for the work. In making a gas-torch 
weld, it is necessary that fusion penetrate entirely through 
the metal. In order to aid this the pieces are usually cham- 
fered or beveled with an air hammer, a grinder, or cold chisel. 
By beveling is meant the grooving or chamfering of the metal 
at the line of the weld, the depth of this groove or V being 
e(iuivalent to the thickness of the metal. 

Beveling is not required on castings or plates lighter than ^/g 
in. in thickness. From Vg in. to ^/jg in. in thickness a chamfer 
of 45 deg. on each piece, or a total angle opening of 90 deg., 
is about right. From ^/jg in. up to the maximum thickness 
weldable by the gas torch, an angle opening of from 60 deg. 
to 90 deg. is used, the angle being dependent somewhat upon 
the nature of the material and the location of the weld. On very 
thick metal a channel with parallel sides, beveled only at the 
bottom, is frequently used. 

131 



132 



GAS TORCH AND THERMIT WELDING 



Under certain conditions it is advisable, but seldom 
economical, to use an oxygen cutting torch for beveling. In 
case this is done, care must be taken that all the oxide pro- 
duced on the surfaces cut by the torch is removed before 
welding. The beginner should start by welding strips of 
rolled iron or steel I in. thick and about 1^ X 6 in. These 
may be welded without the use of a welding rod. The pieces 
must be properly cleaned and free from scale, grease or dirt. 
The operator must wear suitable colored goggles, and should 
grasp the handle of the torch firmly. It is not good practice 
to hold it in tlio finu'ors, because it is impossible to manipulate 




Fig. 94.— The Way to Hold the Torch. 

the flame with as great regularity and control, nor will it be 
possible to do as heavy work without tiring. 

Occasionally, the hose is thrown over the man's shoulder. 
In this case the weight of the torch is suspended and held by 
the tubing, so that it is only necessary to impart the typical 
welding motion to the torch, which can usually be done by 
the fingers. The movement of the welding flame is hindered, 
however, and this method is therefore not recommended. It 
should be used only as a relief when the work is of long dura- 
tion and the operator's wrist and forearm become tired. 

The head of the torch should be inclined at an angle of 
about 60 deg. to the plane of the weld, as in Fig. 94. The 



LEARNING TO WELD WITH A GAS TORCH 



133 



inclination of the head should not be too great, because if it is 
the molten metal will be blown ahead of the welding zone and 
will adhere to the comparatively cold sides of the weld. On 
the other hand, the welding head should not be inclined too 
near the vertical, because in that case the preheating effect 
of the secondary flame will not be efficiently applied. 

There are certain cases, however, where the conductivity 
of the metal is such that it is not necessary to utilize this pre- 
heating. Also certain metals have the property of absorbing 
the gases of the flame. Consequently, in these cases it is best 
that the flame impingement be concentrated to as small an area 
as possible. 

Torch Motion. — The motion of the torch should be away 





Fig. 95. — Different Flame Movements. 



from the welder and not toward him, as closer observation of 
the work can be obtained and greater facility in making the 
weld will be experienced. 

AVhere very thin sheet material is being welded and it is 
not necessary to use a welding rod or wire, a weld may be 
produced by moving the torch in a straight line. It can 
]-eadily be seen that this does not apply to welds which have 
been beveled, and which require the use of filling material, 
for in this case a swinging motion must be imparted to the 
torch to take in both edges of the weld and the welding wire 
a1 practically the same time. 

In comparatively light work a motion is imparted to the 
torch which will cause the incandescent cone to describe a 
series of overlapping circles, the overlapping extending in the 



134 GAS TORCH AND THERMIT WELDING 

direction of the welding, as shown at A, Fig. 95. In order 
that the weld be of a good appearance this mnst be constant 
and regular in its advance. The width of this motion is de- 
pendent upon the size of the material being welded and varies 
according to the nature of the work. In some cases a move- 
ment like a figure 8 is used, as shown at B, but this is a rather 
complicated one for a beginner. In heavier work, if the system 
described were used, a great deal of the motion would be 
superfluous. Consequently, either an oscillating movement, or 
one in which the jet of the torch will describe semi-circular 
zig-zags, as at C, should be used. This confines the welding 
zone; and while the progress is not so fast, it is more thorough 
than the other system for this class of work. 

To the average beginner the regular control of these mo- 
tions is difficult, and considerable practice is required to be- 
come skilled. It is the regularity of these motions that pro- 



•^ 



WeM Finished 

. Here''-. Weld ~\ 

k-/i"-H<— /i"-*t k- 6" H 

Fig. 96.— Plates and Finished Butt Weld. 

duces the characteristic even-rippled surface of good gas-torch 
welding. The progress of a welder and the quality of his 
work can be determined to some extent by the skill with which 
he produces this effect. 

On the practice pieces of |-in. thick material, the operator 
should so manipulate the jet as to take in about \ in. on each 
side of the joint. The point of the cone of the flame should 
be held about Vio in. from the metal, but not actually touching 
it. On thicker metal the distance of the cone tip will need to 
be greater, or about \ in., depending on the size of the tip 
used. It is far better to have the torch too far away than 
too close, as a hole may be blown through the metal. Start 
to weld at the end of the joint, and as the metal commences 
to get red give the torch a swinging motion from side to 
side. Keep this up until the corners of the plates are run 
together clear through their thickness. Then go on until the 
entire length is welded. Do not move the torch any faster 
than necessary to give the metal a chance to run together 



LEARNING TO WELD WITH A GAS TORCH 



135 



properly. Be sure that the bottom edges of the plates are 
melted together before going ahead farther. The plates and 
the way finished weld looks are shown in Fig. 96. 

Care should be taken not to touch the torch tip to the 
metal, as this will obstruct the flow of gas and may cause 
it to backfire and burn inside the tip. In such a case, shut off 
the oxygen at once, then the gas, and cool the tip in cold 
water. Then relight according to previous instructions. 

Do not go back over the weld unless absolutely necessary. 
Do not run the hot metal on top of the cold metal. Do not 
leave blowholes, scale nor low spots in your weld. A blowhole 
is a bubble in the metal. It sometimes occurs alone, and other 
times there are several of them. It maks the metal look spongy 




s 



ABC 

Fig. 97. — Plates Welded Without Proper Divergence. 

or porous and is caused by not properly running the metal 
together or by leaving impurities in the weld. 

When metal is melted, a coating which flakes off is formed. 
This coating is called scale and is bluish steel-gray in color. 

Low spots are unfilled spaces in the metal caused by moving 
the torch too fast or unevenly, - 

The beginner will soon discover that two pieces laid with 
the edges close together will not weld properly, as they will 
at first diverge, as shown at A, Fig. 97. Then they will 
gradually draw together as at B when the weld is about half 
done. From this point on the edges will draw in until they 
overlap about as shown at C. There are two methods of 
overcoming this: The first is to **tack" the two strips at 
intervals, as shown at A, Fig. 98. This method, however, has 
the disadvantage of causing buckling or warping under certain 
conditions. This warping may in some cases be eliminated by 



136 



GAS TORCH AND THERMIT WELDING 



rolling or hammering after welding. The second, and more 
satisfactory method, is to diverge the plates, as shown at B. 
The amount of divergence is dependent to some extent upon 
the thickness and nature of the metal, but it is safe to say 
that this divergence should not be less than 2^ per cent, nor 
more than 6 per cent of the length of the weld. Some operators 
stick to the hard and fast rule of | in. per foot, which is a 
very satisfactory figure in general. However, to obtain the 
best results it is sometimes best to deviate from this, as prac- 
tice and experience dictate. In welding a sheet-metal cylinder, 
it is often necessary to insert a wedge or pin, as shown at C, 







Fig. 98. — Methods of Allowing for Scam Contraction. 

in order to obtain the proper separation and prevent over- 
lapping. 

On very thin sheets, it is usually advisable to flange the 
edges, instead of trying to butt weld with or without adding 
material from a welding rod. The flanges are turned as shown 
at D. The flanges may be tacked as for butt welding, or 
clamped with tongs, as shown. In regular manufacturing work, 
where the welding proceeds rapidly, it is common to have a 
helper move the tongs ahead of the welder. Any warping 
can, as a rule, be easily ironed out of the thin sheets. In some 
cases, the edges are lapped and both edges welded, either using 
a welding rod or not, according to the nature and uses of the 
parts being welded. 

It is very important that the beginner should test his work 



LEARNING TO WELD WITH A GAS TORCH 



137 



by bending the metal sharply at the weld and carefully in- 
specting for defects, which should be overcome on the next 
piece. The tendency of a beginner is to experiment on all 
sorts and thicknesses of metal, but he will progress faster if 
lie sticks to one kind and thickness until he masters it. The 
beginner, as well as the more experienced welder, should occa- 
sionally test his flame to be sure he is maintaining the proper 
neutral flame. This is done by turning off the oxygen until 
a shadowy point appears on the cone. The oxygen is then 
turned on again until this shadowy point just disappears into 
the cone. The reason for this testing of the flame, is that 
changes in temperature of the torch or variations in pressure 
may alter the flame without the operator's knowledge, and 
tlius injure the weld by cither carbonizing or oxidizing the 
metal, according to whether there is an excess of acetylene 



f<-— w 




Fig. 99. — Beveled-Edge Plates and'Flaine Movement. 



or of oxygen. If the tip should become clogged from any 
cause, it should be cleaned out with a soft wire or a piece of 
wood, taking care not to get the hole in the tip out of round. 

Using the Welding Rod. — In starting to use the welding 
or filling rod, it is just as well to begin to weld pieces similar 
in size to those used for the first lessons in welding, except 
that the pieces should be about | in. thick, and beveled on 
one side of the edges only. The amount of divergence is 
judged as in the case of the plain butt-welding work, as shown 
at A, Fig. 99. The flame movement is indicated at B. 

The welding rod should be held and inclined as shown in 
Fig. 100. In this position sufficient quantity of metal may 
be added at the right time. With the welding rod held in a 
vertical position or horizontal, the possibility of the addition 
of an excess of metal, part of which is not fused, is great. In 
adding this metal, care must be exercised that the edges of 



138 



GAS TORCH AND THERMIT WELDING 



the weld are in the proper state of fusion to receive it. If the 
metal is not sufficiently hot, the added material will merely 
stick to the sides and fusion will not exist. It is therefore 
necessary that, by the motion of the torch, fusion be produced 
at the edges of the weld equal with that of the welding rod. 
The usual faults of the beginner are failure to introduce 
the welding rod at the proper time into the welding zone, 
to hold the rod at the wrong angle, or to fuse either too little 
or too much of the rod. The filling material when melted 
should never be allowed to fall into the weld in drops or 
globules. When the proper time arrives to add it, the welding 




Fig. 100. — Using a Filling Eod in Welding. 

rod is lowered into the weld until it is in contact with the 
molten metal of the edges. When in this position the flame 
of the torch is directed around it, and thus fusion is produced. 

It is customary to add metal in excess of that of the original 
section, and round it over nicely. 

There are several very important reasons for doing this. 
First, the weld is reinforced and the strength is accordingly 
increased. Second, in case a finished surface is desired a 
sufficient stock must remain to allow for finish. Third, small 
pinholes or blowholes may be found just under the surface 
of the weld, which do not extend to any depth, and may be 
removed by filing or machining. 



LEARNING TO WELD WITH A GAS TORCH 



139 



In some cases the plates do not start to draw together until 
the weld has nearly reached the center. In a case of this kind 
it is good policy to slow down the welding. After the weld 
has been completed to the center, the plates will commence 
to draw together more rapidly, and in case the plates draw 



p'^'^'-'"\/^y$;^ 



1 -t ] 



Bevel on metal less n i r ^ 

than I or ^n. and over ^^^'^ '"'J ^ f ^V""' 

1- ., ■ 7 over4in. thick where 

8 in. thick . ^ . , , , 

parts must be welded 

from one side only 



1 R K- 




Sections over j in. thick 
Parts are beveled and 
welded on both sides 




Shaft beveled to 
chisel edge for 
welding 



Proper Tnethod of 
beveling shaft over 
2 in. in diam.eter 



How filling material 
must be built up when 
welding different 
thicknesses 



Joint when welding 

convex end to steel 

cylinder 




I 




Weld concave head 
in steel cylinder 



Flat end to be 
welded into tube 



Flange to be welded 



Pipe butt weld 



^^^^y_-z 



Lap weld 




Edge weld. 



Corner weld. 
First side to 



To have a deplh equal " 

to thickness of metal 



Angle corner weld. 
Large angle first 
to show through 
before finishing 



Fig. 101. — Various Examples of Welding Jobs. 



too fast, speed up on the welding until the proper distance 
is secured between the two plates. 

After the beginner has practiced until he can make a good 
weld on the plain and beveled plates, as suggested, he may 
practice on the forms shown in Fig. 101. These forms repre- 
sent most of the kinds he will encounter in the regular run 
of work in a job or general repair shop. 



140 GAS TORCH AND THERMIT WELDING 

Sources of Trouble. — It will be well to repeat to some 
extent, the instructions and advice previously given, in order 
to emphasize the danger points: 

The first source of trouble in making a vi^eld is improper 
adjustment of the welding flame. If the flame is not adjusted 
properly the resultant weld will be inferior. The commonest 
fault is the presence of too much oxygen. In this case, unless 
the welder takes a great deal of care in removing the oxide 
by mechanical means, it will be incorporated throughout the 
weld. The presence of oxide prevents the thorough blending 
of the metal, and therefore decreases its strength. 

Failure to penetrate to the bottom of the weld is the cause 
of a great many defects. Tliis fault is not only that of a 
beginner, but also that of the more skilled operator. Very 
often the desire to complete a weld rapidly will cause the 
operator to hasten over the most important part of his work, 
which is to secure the absolute fusion of the edges at the 
bottom of the weld, before filling rod is added. This defect 
not only reduces the section of the weld, but also produces 
a line of weakness in case the weld is submitted to bending 
or transverse strains. 

When molten metal is added to metal which is not in 
fusion, a weld is not secured. The molten metal merely sticks 
to the cooler metal; this defect is common with careless 
operators. It may be caused by improperly beveling the 
pieces to be welded, by the faulty manipulation of the torch 
or by improper use of the welding rod. 

For the beginner it is at first difficult to distinguish the 
proper temperature at which to add the filling material. 
Usually he applies the filling rod before the edges of the weld 
are in fusion. The adhesion in this case occurs at both edges. 
Occasionally, one edge of the weld is in fusion, but the other 
is not, in which event the adhesion is restricted to one side. 

In some cases the edges of the weld are both at a point 
of fusion too soon. Under these conditions a film of oxide 
may exist on each edge. When a filling material is added, 
adhesion is produced with a film of oxide separating the edges 
and the added material. Quite often an operator, in applying 
-the welding rod to the weld, will concentrate his flame on 
the welding rod and the edges of the weld. As he plays the 



LEARNING TO WELD WITH A GAS TORCH 



141 



torch around the rod he will inadvertently force some of the 
molten metal ahead. The metal not being in the proper state 
of fusion, there will consequently be only a small area of 
adhesion. 

In welding cast iron, copper,- and to some extent steel, a 
very common fault of the beginner is that of forming blow- 
holes or porous sections in the weld. This can be overcome 
by close observation of the work while welding and by certain 
corrective means, the principal one of which is the use of 
proper fluxes and proper manipulation of the welding rod. 



■ mid Here 




-^"^"^^^^^^^^/^/.^ 



saiioM thkjUuh cluep of blvll 



1 - Melt bottom of V 

l-Add filling rod till V is half fiUed 

3- Add filling rod till V is filled 

4- Melt down edge of metal previously 
added and melt bottom of V 



5- Add filling rod till V is half filled 

6- Add filling rod till V is filled 
7 - Proceed as in 4 

Proceed in this manner till weld is 
completed 



Fig. 102.— Method of "Building Up" a Weld. 



It is needless to say that the existence of such defects in a 
weld seriously affect its ultimate strength. 

Occasionally, wields are encountered in which dirt or some 
foreign material is incorporated. This Avill cause porosity 
and an inferior weld, which could readily have been avoided 
by removing the material either before or during the execution 
of the weld. 

Built-Up Welds. — Where steel of considerable thickness is 
to be welded, the Oxweld company recommends the method illus- 
trated in Fig. 102. In the example selected the steel plates 
are f in. thick, beveled 45 deg. on each edge, making an in- 
cluded angle of 90 deg. In doing the work in this way, first 
melt the edges of the bottom of the V together for a length 
cf 1 in. Add the welding rod to this length until the V is 
about half filled. Be sure that the sides of the V are melted 



142 



GAS TORCH AND THERMIT WELDING 



when the rod is added. Then go back over this and fill up 
the V V32 ill- thicker than the original plate. AVhen this length 
of weld is done, melt the edges of the plates ahead down into 
the bottom of the V, and at the same time being sure that the 
end of the weld already finished is melted and flows into the 
botton of the V. Then add to this next section metal until 
a reenforcement of V32 i^- greater than the thickness of the 
plate is formed. Keep on in this way until the plates are 
welded. Near the finish of the weld it is necessary that the 
rod be given a slight swinging motion, similar to the torch. 
This is in order that the top of the V be entirely covered. 

Vertical Welds. — Where plates are to be welded with the 
seam in a vertical position, the same rule for the amount of 
divergence is used as for those in any other position. The 
weld should be started at the bottom and carried upward with- 

.■■We/d .here-. 



f 






i 

( 








y- 







•aU<- >I/V k/vx 



'finished 'Weld-- 



K— — •— IZ'-— >1 

Fig. 103.— The Way to Fill Up Holes. 



out stopping until the weld is completed. Practice on work 
of this kind will give the welder experience in the control 
of the molten metal as no other kind of weld will, and he 
should put in considerable time on this work. 

Filling' Up a Hole. — A thing that every welder should learn 
as soon as he has mastered the simpler welds, is to fill up holes 
properly. A good way to learn is to take a piece of |-in. 
plate and drill three holes in it, \, \ and 1^ in. in diameter, 
as shown in Fig. 103. The beginner should commence with 
the smaller hole first. The weld should be started by melting 
down the top edge of the hole in one place. This will give 
a slight angle to one side. On the face of this angle metal 
is added. The hole is built up by adding metal continuously 
from the bottom to the top until it gradually closes up. The 
welding should be carried on around the hole, however, and 
should not be built up from one side only. When the hole 



LEARNING TO WELD WITH A GAS TORCH 



143 



is properly filled in, the metal should meet at the center. 
Proceed with the 5-in. hole and the 1^-in. hole exactly in the 
same manner. Turn the plate over and clean up the bottom 
side by melting the excess metal with the torch. 

Forming: Bosses or "Putting On" Metal. — The forming of 
bosses, building up missing parts, or putting on metal where 
needed, forms a very important part of a welder's work. Con- 



yteld 
' Here'' 



<!____ 



-3L C 



,-•/ Diam. 
>|-K 

JZI 



Finished 



k- j'-H 



Fig. 104. — Building Up Bosses. 

sequently, the beginner should practice work of this kind 
as soon as he has mastered the ordinary run of welds outlined. 
He can begin by building up bosses an inch or so in diameter 
and 1 in. high on a steel plate, keeping at the work until 
he can produce a boss of fairly regular outline. He can then 
practice on square or rectangular bosses. Built-up bosses of 
this kind are shown in Fig. 104. Since the welder has already 
practiced vertical welds he should have little trouble in placing 



|<-3>1 



■F/nished We id 




- /2 

Fig. 



105. — Putting a Collar on a Shaft. 



his metal where it is wanted. Care, however, should always 
be taken to make sure that there is perfect fusion of the 
added metal and the plate before building up the boss. If 
a good weld to the surface of the plate is not made, the rest 
of the work is worthless. Be sure that all scale and dirt are 
worked out of the metal. 

Another type of built-up weld is shown in Fig. 105. In 
making a weld of this kind for the first time, take a piece 
of 2-in. shaft, 12 in. long and clean off the surface for about 
3 in. at one end. Use a ^As-in. welding rod, and a No. 10 



144 GAS TORCH AND THERMIT WELDING 

Oxweld tip, or its equivalent, and 21-lb. oxygen pressure. 
Place the flame of the torch on one spot of the surface until 
it is melted. Then add the welding rod. Add a layer of 1 in. 
wide and 3 in. long along the shaft. Make this layer ^ in. 
thick. When tliis strip is finished, weld another strip on top 
of it, starting at the end just finished. This gives a strip 
of added metal 1 in. wide, 3 in. long and ^ in. thick. When 
this is done, start another strij) at the side of this, being 
careful that the metal of the shaft is melting before the welding 
rod is added and also that the edges of the first two layers 
are at the same time melted down to the shaft. Proceed with 
the welding exactly the same as just described, adding strip 

/We/dHere-:^ .-Finished Weld-. ^ 

,-\f\S\J\j 





Fig. 106.— Building Up Gear Teeth. 

after strip, side by side, until the end of the shaft is covered 
all around. Ilemember that the shaft must be melted before 
any metal can be added, that each layer must be melting before 
another layer can be added to it, and that each strip must 
be welded botli to the shaft and the strip next to it. AA^hen 
the shaft is completely covered, the end of the weld should 
be gone over with the welding flame, in order to clean it up and 
to be sure that a weld is produced at this point. 

Following the building-up work just outlined, it is a good 
thing to practice building up worn- or broken-out teeth in 
old or scrap steel gears, as shown in Fig. 106. Before a 
welder attempts to do any actual repair work on gears, how- 
ever, he should first learn more about expansion and contrac- 
tion, and the metliods of overcoming their effects. 

WELDING BACKWARD 

In an article published in tlie "Acetylene and Welding 
Journal," London, England, Capt. D. Richardson describes 
a method of welding which differs considerably from the gen- 
erally accepted American practice. 



LEARNING TO WELD WITH A GAS TORGH 145 

In 191 G, M. IvouUeau, ;i Froiu-h ucetylene engineer, was seat by his 
firm to Italy in connection witli tlie manufacture of large welded pro- 
jectiles. The welds were being made by welders with little knowledge 
of the process and examination showed that from the number of de- 
fective welds obtained it would be difficult to get worse results. The 
welds were porous, adhesion was common, and the solidity of the 
joints was extremely bad. The supervision of the 1000 to 1200 welders 
distributed through seven or eight different works was a serious 
problem. The daily consumption of oxygen and carbide, at a cost 
of thousands of francs, in producing work of the type described made 
it an urgent economic problem to bring about improvement. Faced 
with these various problems, j\I. Roulleau, after experiment, introduced 
the method of welding backward into the various Italian workshops 
which came under his technical supervision. This change in method 
produced excellent results and on returning to France after a mission 
of three years in Italy, M. Roulleau collaborated with the Union de 
la Soudure Autogene with a view to a wider application of his 
method. 

Welding backward may be defined as the method of executing 
a weld in which the welding rod follows the torch as opposed to 
preceding it. Or again, it may be defined as a method in which the 
flame is inclined towards the welded portion. A fuller and perhaps 
better definition would be : The flame is inclined backwards and only 
undergoes a slight transversal motion in addition to its regular ad- 
vancement, the welding rod follows the flame and is given a movement, 
the end of the rod always being molten. 

It is claimed that, having acquired the method of welding backward, 
the welder will find it easier to execute welds and that the penetra- 
tion is always satisfactory ; adhesion is almost impossible ; the metal 
is sound; there is a diminution in the amount of oxide, and the metal 
is more ductile. Finally, that the speed of welding is greater than 
with the old method from which it will be gathered that there is 
economy in labor and gases. The economy in the consumption of filling 
material is of the same order as it is possible to reduce the beveling 
angle. 

APPLICATIONS OF METHOD 

This method of welding is applied mainly to steel plate above Vic 
in. in thickness. It should be used on all plates falling in the range 
of J to ^ in. in thickness. 

The process is particularly valuable for certain industries such as 
the manufacture of boilers, etc. 

Its application to mild steel has been specially studied. A number 
of experiments have shown that welding backward gives better results 
than the usual method when welding steels with a higher carbon con- 
tent—medium and hard. It is not satisfactory for aluminum welding 
and gives indifferent results when welding cast iron. On the other 



146 GAS TORCH AND THERMIT WELDING 

hand, the first series of tests in using the method when welding copper 
and brass have proved satisfactory. 

Wlien comparing this metliod of executing welds with other methods, 
one might say that welding backward is a "more mechanical" method. 
From this it follows that more definite rules have to be observed in 
executing welds and it is advisable, especially for beginners, to strictly 
observe the rules laid down. These instructions, which are the result 
of investigation, may subsequently be modified and added to, but in 
the meantime they give good results and should be followed. 

For example, it will be noticed that for this method of welding, 
the edges of the two pieces of metal to be welded should be chamfered 
or beveled, so that when they are placed together, the two beveled 
edges form a V. Although the angles of the bevel can be reduced, 
beveling is still indispensable, even on thin material. 

PREPARATION OF MATERIAL 

The parts to be welded are prepared in the ordinary way, tacks, 
or short welds, at intervals of from 2 to 6 in., according to the 
thickness of material may be used. In the absence of jigs, the parts 
are supported so that the lower edges are in the same horizontal plane. 
The angle of the V formed by the two beveled plates should never 
exceed 90 deg., and, as already mentioned, for this method can 
be distinctly less. Beginners can gradually reduce the angle of the 
V from the previous standard of 90 deg. until they arrive at GO deg. 
for material I in. in thickness or above, and for material between J 
in. and i in. an angle of between 45 and 50 deg. can be used. 

The beveling should be carefully done and extend the full depth of 
the plates as partial beveling will produce defective welds. 

The power of a torch, in other words, the quantity of heat which 
it is capable of giving out in a given time, is generally measured by the 
number of cubic feet of acetylene burnt in an hour with the flame 
perfectly regulated. The rule which has been adopted for welding 
steel by the usual method of executing welds can be followed, namely, 
that the consumption should be about 5 cu.ft. of acetylene per 
hour for every Vie in. in thickness. So that for material '/le in. thick, 
a torch consuming about 15 cu.ft. per hour would be required, for 
I in. one consuming 30 cu.ft., and so on. However, it will be found 
that beginners obtain the best results by using a less powerful torch 
than indicated, whilst the more expert welder rapidly reaches the stage 
where he can advantageously use a more powerful one, as for example, 
for Vs-in. material a torch consuming 5.3 cu.ft.; for '/le-in. material 
one consuming 20 cu.ft. ; and for |-in. 40 cu.ft. 

SIZE OF ROD 

The choice of the right size of welding rod is of great importance. 
A rod that is too small melts too freely, has a tendency to burn, and 
is distributed badly. The defects of adhesion and oxide inclusions are 



LEARNING TO WELD WITH A GAS TORCH 



147 



common. If the wire is too large, tlie rate of welding is retarded, the 
molten bath is cooled, and it is difficult to add the metal uniformly. 
In both cases burning and overheating of the welding rod and material 
are likely to take place. 

The following table gives the sizes of rod for welding various 
thicknesses : 



Thickness 




Diameter of Wire 




to be Welded 




Decimal 




In Inches 


S. W. G. 


Equivalent 


Nearest 1/64 


1/S 


14 


0.081 


5 


5/32 to 3/16 


11 


0.116 


8 


1/4 to 9/32 


8 


0.160 


. 10 


11/32 to 13/32 


6 


0.192 


12 


above 


4 


0.232 


ir. 



POSITION OF TORCH 

The flame of the torch should be given a definite inclination. In 
certain cases and especially with expert welders, familiar with the 




Fig. 107. — Position of Torch and Eod for Backward Welding. 



backward method of executing welds, this inclination of the flame to 
the plane of the weld is very small, in other words, the flame is almost 
perpendicular to the weld. However, it has been found that an angle 
of 20 deg. gives the best results, that is to say, the angle between 
the nozzle of the torch and the perpendicular should be 20 degrees, 
the flame being turned backwards as shown in Fig. 107. Beginners 
should pay particular attention to obtaining and practically working 
at this angle of inclination. 

In welding backward it is the welding rod that is given a move- 
ment and not the torch. The torch is therefore held in such a manner 
that the flame advances along the bevelled faces with as great a 



148 



GAS TORCH AND THERMIT WELDING 



regularity as possible, the rate of niovenieut being in proportion to the 
speed of welding. A very slight transversal movement may be given 
to the torch to produce more rapid fusion of the two bevelled faces. 
The white cone of the flame should penetrate very deeply into the 
angle of the V as shown in Fig. lOS. If held too high as shown in 
Fig. 109 the melting at the bottom of the V is not sufficient, the size 





Fig. 108. — Position of Flame. 



Fig. 109. — Wrong Position. 



of the weld is unnecessarily increased, the metal near the surface is 
overheated and the speed of welding is diminished. 

The penetration of the white cone should be carefully observed if 
the advantages, economy and quality of welds, which can be obtained 
by welding backward are required. 



HOW TO HOLD THE ROD 

The melting of the metal is produced, as previously explained, be- 
hind the torch and not in front as is the common practice. 

This melting is not obtained by the welding cone of the flame, but 
by the additional heat contributed by the envelope of the flame, the 
torch being inclined towards the rear, in other words, towards the 
welding wire. 

The position of the welding rod and its movement should be closely 
followed. The rod is inclined to the line of welding, in the advancing 
direction, that is to say, in the opposite direction to the inclination 
of the flame. The best angle of inclination, between the weld and the 
rod, has been found to be 45 deg. for material about J-in. thick, and 
for thinner material, say J-in.. an angle of about 30 degrees. This in- 
clination is maintained whilst the welding rod is given its proper move- 
ment in the line of welding. This movement for the thicker material, 
say, about -}-in.. consists in alternately moving the molten extremity 
of the wire from one side to the other of the line of welding, as shown 



LEARNING TO WELD WITH A GAS TORCH 149 

ia the small illustration in Fig.lOT. The movement for material less 
than this thickness becomes first of all ellipsoidal or gyratory, and then 
for materitil about ^-iu., and especially when the material is about Vis 
in., the movement is translated into a reciprocating one without any 
transversal movements, as shown in Fig. 110. In both of these cases 
the extremity of the wire remains continually in the molten bath. 

In order that the line of welding should present an homogeneous 
appearance, it is advisable to operate in the manner already laid down 
and with the same speed at the conunencement and completion of the 
work. If, say, one of the extremities of the weld is attacked too 
soon with the torch, free fusion and regular advancement are not 
obtained until after a certain time, with the result that irregularities are 
noticeable at the beginning of tho weld. To avoid this the plates 
should be preheated for a length of a few inches with the torch, so as 
to obtain, at the beginning, regularity, and a normal rate of welding. 



Fig. 110. — Rod Movement When Welding Thin Metal. 

The torch and the welding rod being held in the manner indicated, the 
cone of the flame is directed so as to well penetrate into the angle 
of the bevel, and the first molten bath is obtained by giving the torch 
a slight gyratory movement, immediately after which the extremity 
of the welding rod is introduced into the molten bath and the torch 
is then given its regular advancing movement. 

The welding rod, on the other hand, follows immediately after the 
flame, and describes a recipi'ocating or a more or less elliptical and 
longitudinal motion, according to the thickness of the metal, as indi- 
cated and shown in Figs. 107 and 110. taking care to always maintain 
the given angle of inclination. The weld is thus obtained in a normal 
and very continuous manner. Care must be taken to use a welding 
rod which satisfactorily fills the lines of welding, without excess or 
insuflicient addition of material. If necessary, the position of the 
torch is changed when the extremity of the weld is reached in order 
to obtnin a clean finish as is usual with the ordinary method of 
welding. 

The melted metal being attacked in the rear, as a result of the 
inclination of the flame, the bevelled faces are always well melted ; 



150 GAS TORCH AND THERMIT WELDING 

the weld, is what is commonly said to be well penetrated and the 
defect of adhesion is almost impossible. However, it is advisable not 
to travel too fast so as to give the bevelled surface sufficient time to 
melt freely, otherwise candles of molten metal will appear on the 
underside of the weld as a result of the addition of too much heat 
at the bottom of the V. 

From the point of view of good penetration of the metal and the 
absence of the defect of adhesion, welding backward offers considerable 
advantage over other methods of executing welds and is capable of 
entirely eliminating these defects. 

Etching tests on welds obtained by this method show perfect join- 
ing between the metal of the plate and the added metal. The welds 
show distinctly less oxide inclusions than those obtained by the or- 
dinary methods, and are free from blowholes. In addition they possess 
ordinary hardness and the remaining mechanical properties are more 
regular. 

Bending tests have given good results. It is possible to fold the 
weld without starting a crack, which is a very good indication of 
excellent elongation properties and good penetration of the weld. The 
tensile strength of the weld is also greater than that of ordinary welds 
and improvement in the other mechanical properties is obtained. 

INSTRUCTIONS FOR LEAD BURNING 

The "Eveready" instruction book, issued by the Oxweld 
Acetylene Co., gives the following hints on lead burning: 

The size of the flame used in lead burning depends almost entirely 
upon the class of work. The 0-H3 and 1-H3 tips are used on very 
light sheet lead and similar work, the 2-H3 tip on heavy sheet and 
light storage battery work, and the 3-H3 and 4-H3 tips on general 
storage battery work. 

In all cases where lead burning is to be done, it is essential that the 
edges of the parts to be burned are first cleaned. Otherwise a film 
of oxide will form on the molten surfaces of the metal, which will 
tend to keep the metal from flowing together, slow down the work 
and quite possibly result in a poor joint. Clean the edges to be joined 
and also clean the surface a short distance back from the edges, either 
with a lead scraper or a wire brush. 

It is extremely difficult to burn lead which has been subjected to 
the action of a strong acid, such as the sulphuric acid used in storage 
batteries. Where it is possible to neutralize the acid by a solution of 
ammonia or sodium bicarbonate without getting any into the battery 
and injuring it, that method is allowable. It is decidedly better in 
all cases, however, to wipe dry the parts to be burned and then scrape 
them bright. The scraping will remove the layer of lead which has 
been affected by the acid and will insure a good joint. 



LEARNING TO WELD WITH A GAS TORCH 151 

LEAD BURNING-STICKS OR WELDING RODS 

In some cases additional metal is fused in to completely fill the 
parts being burned or for reinforcing the joint. Where extra metal 
is added, the "burning sticks" or rods employed for this purpose are 
either pure lead or lead containing a percentage of antimony. Pure 
lead rods are preferable for working on sheet lead or for any part 
which may be subject to bending strains. Rods containing antimony are 
preferable where the work is to be threaded or where it must be 
rigid enough to withstand twisting strains, as for instance storage 
battery terminal posts. 

Hold the torch so that the flame is almost perpendicular to the 
surface of the work and the white cone almost touches the metal. Be 
careful, however, not to jab the tip of the torch in the molten lead, and 
under no circumstances hold the torch tip any closer to the work than 
may be necessary to play the tip of the inner cone of the flame upon 
it. In all lead burning it must be remembered that the melting point 
of lead is low and that as soon as it reaches the melting point it will 
flow rapidly and unless care is exercised it may get beyond the control 
of the operator. The chief thing to learn is to know when the lead 
is flowing properly and to lift the flame immediately from that part of 
the work so that no excess melting will be done. Should the metal 
start to run away, lift the torch and allow the work to cool before 
attempting to proceed. 

When adding metal the torch flame should be played simultaneously 
on the rod and along the edges of the work to be joined so that they 
will reach the fusion point at the same time. It does no good to 
deposit molten lead upon cold lead. All the lead must be melting, 
otherwise it will not fuse together. 

Do not allow the rod to touch the metal being worked upon, as it 
will probably stick and become firmly attached. 

LAP JOINTS 

In burning sheet lead it is always better, wherever possible, to lap 
the joints, that is, lay the edge of one sheet of lead i to ^ in. over the 
edge of the other. The overlap of both sheets must be thoroughly 
cleaned, not merely the edges of the sheets. After placing the sheets 
in position tap lightly with a wooden mallet along the line of lap to 
bring the two sheets together. Though lapped joints are sometimes 
burned without the use of burning sticks, they are not so strong as 
when a filler is used. In the former method the torch flame is merely 
played along the edge of the overlapping sheet. With a little practice, 
this class of joint can be made at high speed. 

BUTT JOINTS 

When the edges of the work are butted together (not lapped), it is 
possible to burn them together without the addition of metal. Although 
this makes a very neat appearing joint the use of the rol3 will insure 



152 GAS TORCH AND THERMIT WELDING 

a stronger joint with less cliance of leaving unburned spots in the 
seam. For a butt joint, the sheets must be cut true and must lie true 
while being burned. Tapping along the line of burning with a wooden 
mallet about 6 in. ahead of the burn is desirable. 

In tacking, burn a small spot at each end of the seam and if it is 
a long one, burn small spots at about G-in. intervals to keep the edges 
from pulling apart. This is especially important on vertical seams, but 
it is also desirable on horizontal seams to prevent trouble that may 
be caused by the edges spreading. 

The movement or play of the torch flame is largely a matter of 
choice on the part of the operator. Some operators prefer a slight 
circular movement, progressing along the line to be burned, while 
others prefer to play the flame alternately from each side of the line 
of burning. For the beginner, the circular movement is probably the 
better. 

In burning horizontal seams lapped or butted joints may be used, 
and it is desirable to tack before burning. If extreme strength is 
desired, use the lap joint. In vertical seams lapped joints should be 
used, and should be tacked before burning. Start from the bottom and 
work upward. For overhead seams lapped joints should be used and 
should be tacked before burning. These seams require skill on the part 
of the operator, and considerable practice will be found necessary before 
good burning and neat resvilts are obtained. 

STORAGE BATTERY BURNING 

In battery repair work there are several operations that call for 
lead burning. It should be noted that great care must be used to see 
that the work is thoroughly scraped bright before burning and that 
all oxide and traces of acid are removed. For rods, use antimonial 
lead if certain that the plate connectors are made of antimonial lead ; 
if uncertain, use pure lead. 

Note: Antimonial lead after scraping has a silvery appearance as 
compared with the blue tinged color of pure lead. Antimonial lead 
is also much tougher and harder to scrape or pare with a lead scraper 
or knife. 

In burning plates to plate connectors, set up the plates in a burning 
rack or comb, which will provide for proper spacing and true align- 
ment. The lugs of the plates must extend above the top of the comb. 
Place the post in position before attempting to burn the lugs together 
on a lead strap. To burn, play the flame along the ends of the lugs 
and when they are molten add metal from the rod and form a strap 
connecting them all and the post. A comparatively large flame should 
be used to insure perfect joints because the plates must be fused 
perfectly to the strap and post. 

If a slotted plate strap or connector is used, set up the plates as 
described above with the lugs extending up into the slots. To burn, 
play the flame along the sides of the slots to bring them and the 



LEARNING TO WELD WITH A GAS TORCH 153 

lugs to a melting point at the same time, then add metal from the 
rod to fill up the slots and flush the strap off smooth. 

BURNING CELL CONNECTORS OR TERMINALS TO TERMINAL 

POSTS 

The connectors should be tapped lightly with a small wooden 
mallet until they fit snugly around the terminal posts. To secure a 
good burn, it is necessary that tlie surface of the top of the terminal 
post be about | in. below the top surface of the cell connector or 
battery terminal. If necessary, the post should be cut off to insure 
this feature. To burn, play the flame on the top of the post and bring 
it and the inner wall of the connector to a molten state, forming a 
molten pool. To this add metal from the lead rod. As the pool fills 
up, be sure to watch that the metal on the inside wall of the con- 
nector flows into and with the added metal. Continue until the added 
metal is flush with the top surface of the connector. Then allow the 
connector or terminal to cool sufficiently so that the lead will not 
crumple when brushed, clean the top with a wire brush, and again 
apply the flame and add enough lead to smooth off and finish the job. 

It is sometimes impossible to burn on a connector or terminal in 
one complete operation, because the metal surrounding the cavity be- 
comes overheated. In sucli cases, stop work as often as the lead 
seems to be running too rapidly, and allow it to cool before proceeding. 

In burning on a terminal in which the end of a cable is imbedded, 
protect the rubber insulation on the cable with a strip of wet cloth, 
to avoid burning it. 

In battery repair shops it is often necessary to build up a terminal 
post which was drilled out when the battery was torn down. When 
building up a post, a mould should be used to hold the metal in place. 
This mould can be made of sheet metal and should be tapered so as 
to be easily withdrawn from the finished work. Be sure that the 
top of the post is in a molten state before adding lead, so that the 
post and the metal added will be solidly . fused. Unless this is done, 
the joint will be weak. 

LEAD BURNING DATA 

Approximate results obtained with Eveready Lead Burning Torch: 
Pressure Gas Consumption 

Oxygen Acetylene Oxygen Acetylene 

lb. per lb. per cu.ft. cu.ft. 

Size of Tip sq.in. sq.in. per hour per hour 

0-H3 2 to 3 2 to 3 1 1 

1-H3 2 to 3 2 to 3 2 2 

2-H3 2 to 3 2 to 3 3 to 5^ 3 to 5 

3-H3 3 to 4 3 to 4 6 to 10 6 to 9 

4-H3 3 to 5 3 to 4 9 to 12 8 to 11 



CHAPTER X 

MAKING ALLOWANCE FOR EXPANSION AND 
CONTRACTION 

Through his practice work, as already outlined, the be- 
ginner in welding has learned a little about the trouble that 
expansion and contraction may cause when proper allowance 
is not made. This was shown to some extent when he at- 
tempted to butt-weld two plates set close together. The 
remedy in that case was to allow for the contraction of the 
cooling metal and weld, by diverging the edges of the plates. 
From this example alone he can get a slight idea of the tre- 
mendous stresses often set up when, for instance, a broken 
spoke in a flywheel is welded Avithout proper allowance being 
made for the amount of expansion in heating and contraction 
in cooling. These stresses ynay be so great as to quickly cause 
other fractures, or be of such a nature as to cause the sub- 
sequent destruction of the wheel. Different metals conduct 
heat with varying degrees of speed, that of copper being 
much more rapid than that of steel. On this account the 
welder must know something of the characteristics of the 
metal he is working on in order to obtain good results. How- 
ever, except for the amount of expansion and contraction, the 
same general rules apply to all cases. It should be kept in 
mind at all times, that nothing can prevent this expansion or 
contraction of metals when heated or cooled, and that allow- 
ance in one way or another must always be made. 

Where the ends of a broken bar are butt-welded together 
the parts are free to expand as they are heated, unless rigidly 
held. Suppose, however, that they are free to move, then 
when heated the broken ends will move toward each other, 
pushing the two parts of the bar in opposite directions when 
the heated ends touch. After the weld is complete, the cooling 
will cause the metal to contract, drawing the two parts of the 

154 



ALLOWANCE FOR EXPANSION AND CONTRACTION 155 

bar closer together. In somo cases the bar may be shorter than 
before, depending on the care and skill with which the weld 
was made. Owing to the fact that the parts of the bar are 
free to move no bad stresses are set up. Again suppose the 
bar happened to be part of a frame, as shown in Fig. 111. 
Then when heated at the break A, the ends could only move 
toward each other, in certain cases causing these ends to 
upset, or become thicker. After the weld was completed, the 
metal would start to contract, the tendency being to pull the 
cross ends in as shown at B and C. If the metal was ductile 
— that is, would stretch — it would probably actually bend in 
as suggested. Wrought iron or steel, for example, would 



Fig. 111. — Broken Frame with Preheating Zones Indicated. 

probably do this. Cast iron would probably break. Aluminum 
would break or bend, according to the alloy used. In any 
case it would be a poor job, no. matter how well the welding 
work itself was performed. The way to obtain a good job is 
to heat the frame at D and E, so that these side bars will 
expand as much as the middle one will while being welded. 
The contraction on cooling will then be the same on all three. 
Local heating like this is not always sufficient, and it is often 
necessary to heat the whole piece. 

Sometimes conditions are such that neither a part, nor the 
whole of a piece may be heated properly. 

We may then use a jack to open the break in the middle 
bar a short distance, make the weld, and then slowly loosen 
the tension on the jack as the metal contracts. Or we may 



156 



GAS TORCH AND THERMIT WELDING 



wrap wet cloths or wet asbestos or clay around the middle bar, 
close to the weld and keep cold water running on it while 




Fig. 112. — Preheating Furnace, Using Charcoal. 

welding. This simply holds the expansion to a limited area 
and should be employed only when no other method is possible. 
Undoubtedly the better method in nearly all cases is the pre- 




FiG. 113. — Preheating Furnace on an Iron Table. 

heating of the article or a portion of it, though in each case 
proper judgment must be exercised. 

The simplest way to preheat work is, as a rule, to build a 
temporary firebrick charcoal furnace, the form depending on 



ALLOWANCE FOR EXPANSION AND CONTRACTION 157 

the shape of the work. Where a piece like the frame just men- 
tioned is to be heated all over, a furnace something like the 
one shown in Fig. 112 is very handy. Often an iron table and 
furnace like the one shown in Fig. 113 will serve for numerous 
repair jobs. 

USING HEATING TORCHES 

Where the nature of the work makes the use of charcoal 
unsuitable or impossible, a coal gas torch, kerosene torch, or 




Fig. 114. — Crude Oil or Kerosene Preheater in Action. 




Fig. 115. — Using Two Burners to Preheat a Large Gear. 

even the welding flame itself, may be used. The last, however, 
is too expensive to use except where absolutely necessary. As a 



158 



GAS TORCH AND THERMIT WELDING 



rule, a coal gas torch makes a very satisfactory means of pre- 
heating if it can be used. In using any preheating flame it is 
best to build up with firebrick or asbestos in such a way as to 
confine the heat where wanted. This also saves fuel. An Ox- 




Fig. 116. — A Gas and Preheat inf:^ Torch. 



weld preheater using any grade of fuel, crude or kerosene oil, 
is shown in action in Figs. 114 and 115. This has two burners, 
and has to be pumped so as to have about 25 to 50 lb. pressure 
to get good results. The large size weighs 110 lb. One big ad- 
vantage of a burner of this type is, that it may be carried any- 




FiG. 117. — Portable Electric Blower-Type Gas-Burning Preheater. 

where and used. Where a shop has a compressed-air system 
and illuminating gas, the type of torch in Fig. 116 will prove 
exceedingly satisfactory. In case a shop does not have a com- 
pressed-air system, but has gas and electricity, the apparatus 
shown in Fig. 117 may prove useful. This is made by the 



ALLOWANCE FOR EXPANSION AND CONTRACTION 159 

Tyler Manufacturing Co., Boston. The motor driving the fan 
is of the universal type, operating on either alternating or direct 




Fig. 118. — Portable Preheater Mounted on a Stand. 




Fig. 119.— Iron Table With Firebrick Top. 



current. One motor will supply air enough for four regular 
size burners. 

Another torch is shown in Fig. 118. This also uses illu- 
minating gas, the air being supplied by means of an electric 



160 GAS TORCH AND THERMIT WELDING 

driven fan. This device is made by the North American Manu- 
facturing Co., Cleveland, Ohio. It is claimed that from 500 
to 2500 deg. F. may be obtained with this torch. 

For welding work of all kinds where proper alignment must 
be maintained, a table with a heavy cast-iron top is almost in- 
dispensable. Tables of this kind may be obtained from almost 
any of the supply firms. The Imperial Brass Manufacturing 
Co., Chicago, supplies a table with a firebrick top, as shown in 
Fig. 119. This kind of a table is very handy, as it enables the 
welder to construct firebrick furnaces of all kinds, and to so box 
in his work as to conserve all the heat possible. It also brings 
the work up to where he can work on it to the best advantage. 

COOLING WORK 

The cooling of steel or iron work after welding is often as 
important as the preheating. Some work must be annealed 
after it has cooled, by heating to a red heat and then slowly 
cooling again. Small parts may be buried in slacked lime, ashes 
or the like. Flat work may be laid in a sheet-iron box partly 
filled with lime and covered with sheet asbestos or more lime. 
In any case, the weld should be protected as much as possible 
from drafts. Where a firebrick furnace has been built up around 
some part, it may be closed in and the work allowed to cool as 
slowly as possible. The welder must use good judgment in all 
eases. It must not be thought that preheating is only necessary 
to take care of expansion and contraction, for while in small 
work this is often the only consideration, on large work it saves 
expense. By this it is meant that the use of charcoal, gas or 
other heating mediums is nuicli cheaper than to try to bring 
the parts to be joined up to a welding heat with the welding 
fiame alone. 

The way in which expansion and contraction will take effect 
often requires considerable study. If the work can be heated 
all over, this is often the best way. As already mentioned, 
this is often not possible, so in order to assist the beginner, a 
number of examples will be given showing just where certain 
jo])s should be preheated to get good results. A good thing to 
keep in mind as to where to preheat, is to imagine a wedge 
driven in at the break and note what places this action would 
put under strain. 



ALLOWANCE FOR EXPANSION AND CONTRACTION 161 



THE WIEDERWAX PREHEATER 

A preheating furnace suitable for both preheating and slow 
cooling is shown in Figs. 120 and 121. This heater is made 




Fig. 120. — The Wiederwax Preheater. 



i **;■' * '\ 









eat^A^' 




Fig. 121. — Showing the iSlow Cooling Oven. 



by the Geist Manufacturing Co., Atlantic City, N. J., and is 
known as the "Wiederwax preheater. It has. eight gas burners 



162 



GAS TORCH AND THERMIT WELDING 



entering from each end and extending to the middle. This 
makes it possible to heat any section or all of the top, as desired. 
The top has parallel grate bars to support the work and the 
gas burners are buried in pieces of refractory, heat-retaining 
material, so that parts are heated with the use of a minimum 
amount of gas. After the welding is done, the work is placed 
in the oven underneath the heaters and slowly cooled. 

When using this heater or welding at any time, the work 
should be covered with asbestos sheet as much as possible. 

This concern also makes a floor-type of preheater for heavy 
work. 

SUGGESTIONS REGARDING THE WELDING OF GRATINGS AND 

PULLEYS 

S. "W. Miller, of the Rochester Welding Works, writing in the 
"American Machinist" says: 

It should be clearly understood by the welder that in a 
restrained weld, which is one entirely surrounded by metal, such 






t 


o 




B__ 








1 




'— 




A 

I 



Fig. 122.— A Restrained Weld. 



Fig. 123.— Grating to be Welded. 



as a crack in the center of a plate, it is impossible to get rid 
of both strain and distortion ; a moment 's thought will make 
this clear. Such a crack is shown in Fig. 122. When crack A 
is welded the metal between B and C is heated hotter than that 
between D and E, and F and G, and, being soft, the expansion 
crushes it; so when cooling occurs, B to C contracts more than 
the rest of the plate, which either causes a crack, or leaves a 
tensile strain in the plate. It is true that the strain can be re- 
lieved by annealing, but that leaves a distortion of some kind; 
if the distance BC be the same as originally, the thickness along 
BC must become less, and vice versa. 

If this is not clear, let the welder heat a spot in the center 
of a |-in. plate of steel, and see what happens. 

In a partly restrained weld, such as Fig. Ill, it is evident 



ALLOWANCE FOR EXPANSION AND CONTRACTION 163 



that the method of preheating described produces expansion of 
the part to be welded in such a way that the opening of the 
crack is tlie same at all points in its lengtli. In other words, 
there is no variation in the width of the crack after expansion 
and before welding. 

This is an important principle to be noted in expansion and 
contraction problems; it may be worded as follows: A crack 
must always be opened the same amount at every point in its 
length, if both strain and distortion are to be avoided. 

Fig. 123 shows the condition of a grating when received at 
the welding shop. The quickest and cheapest way to weld this, 
if three men are available, is to double bevel all breaks; use 
three men to weld A, B and D at the same time, first on one 
side and then on the other; clamp the piece on a flat table to 



/Heating Zone-, 





Fig. 124. — Eesult of Improper Fig. 125. — Welding a Broken 

Heating. Pulley. 

keep it straight and let it cool. Then have one man heat at E 
with a torch, and let another weld at C as at the other points. 

If only one man is at hand, he should weld B first; then, 
keeping bar Z> hot, weld B; next, keeping both B and D hot, 
weld A; allow the piece to cool, heat E and weld as before. 

This brings out the principle that one should never finish 
a weld in the center of a piece, unless it is absolutely necessary ; 
always finish at the edge. 

It will be seen that the method just described keeps the sides 
of the cracks parallel, and that if the proper allowance is made 
for contraction, there will be no strains left in the welded piece. 

The matter may be made clearer by a study of Fig. 124, 
w-hich indicates the result of improper heating. Heating the 
corner H for crack B will lengthen sides A and C, the resultant 
of these being in the direction of D ; so that the upper part of 



164 GAS TORCH AND THERMIT WELDING 

crack B will lie as in the dotted lines, and after welding and 
cooling there will be strains at E, F and (/ which will surely 
cause cracks in service, if not at once. 

With a smaller grating it is possible that there would be 
spring enough in the bars to avoid breakage; but there would 
be strains that could be avoided by other methods. The basic 
principle of all welding is to weld without having either strain 
or distortion in the finished piece. 

With regard to pulley welding such as shown in Fig. 125, 
the rim should be heated on both sides of the broken spoke to 
lengthen the rim and pull the crack A open, and the spoke 
should be kept as cold as possible. Also all spokes should be 
welded from both sides. 

The break at B should be opened by heating the spokes next 
to it so that when the crack is open enough, the edges of the 
break will be the same distance from the center; this of course 
means different amounts of lieat in the two spokes. 

AUTOMOBILE CYLINDER WORK 

The next example is a block of two cylinders, broken as 
indicated in Fig. 126. The first break to be repaired is in the 
water jacket at A. The second break is on the flange at B, and 
the third is on the water jacket as shown at C. The fourth 
crack D is on the inside of the water jacket, necessitating the 
removal of part E by drilling in order to get at it. 

To weld any of these cracks, except B, without preheating 
would break the casting from expansion w^hcn the flame was 
applied to it, and contraction when the weld cooled. The pre- 
heating in this case means the heating of the entire casting 
alike. To do this, build a furnace of firebrick, as shown at F. 
In order to give enough draft for the fire, the bottom bricks 
should be set about 1 in. apart. The cylinder block, with the 
cracks properly chipped and beveled, may then be placed on 
the first layer of brick and the walls built up around it. These 
walls should be so built as to allow about 6 in. between them 
and the cylinder. That is, there should be space enough allowed 
to turn the cylinder without knocking down the walls when 
ready to weld. About three or four shovelfuls of charcoal should 
he put around the cylinder and a little kerosene put on it and 
lighted. After the charcoal has become thoroughly lighted and 



ALLOWANCE FOR EXPANSION AND CONTRACTION 165 

the cylinder slightly heated, more charcoal should be added until 
half the casting is covered. Then a piece of sheet asbestos 




■^ ■^. - ' ^---r Tr^^-Tg-St= _ 



-^-- Air Holes / 

Fig. 126. — Broken Motor Cylinder Block and Preheating Furnace. 

should be put over the top, and a few holes punched in it for 
draft. Where the break is bad, leave the cylinder alone until 



166 GAS TORCH AND THERMIT WELDING 

it reaches a dark red all over, then remove the asbestos and 
turn the cylinder so that the part to be v^^elded first is upper- 
most. Then replace the asbestos and cut a hole in it so that 
the break can be reached with the torch and welding rod. Never 
take the cylinder out of the fire to weld. 

In working on automobile cylinders it is usually unnecessary 
to preheat at all when welding lugs; in cases where it is neces- 
sary, only a very slight amount is needed — just enough so the 
cylinder cannot be handled without tongs. 

Usually ordinary jacket cracks can be welded at much less 
than a red heat. In fact if a red heat is used, in most cases 
the cylinder bores will warp badly. 

The important points in cylinder welding are a uniform 
soaking heat, not necessarily very high, welding on rising tem- 
perature, and slow cooling. 

Never weld an important break in a cylinder block without 
about three hours slow preheating, never allowing the fire to 
die down. Then pack it in loose asbestos in the fire, to insure 
slow cooling. Of course, there are exceptional cases where the 
break is so bad that high preheating is needed. 

Care must be taken not to let melted metal run down into 
the water jacket. Be sure to work out all dirt or scale, and do 
not leave any pinholes or blowholes. In order to prevent the 
bore of the cylinder from scaling, it should be coated with oil 
and a thin coating of graphite applied before the cylinder is 
placed in the furnace. After welding the graphite can be cleaned 
off with a piece of waste. 

For crack B, the cylinder seldom needs to be preheated, as 
previously mentioned. The inner weld C is made the same as 
crack A. Crack D, being on the inside of the water jacket, is 
treated differently. A portion of the outer wall of the water 
jacket is removed by drilling, as previously mentioned. The inner 
weld is made, after which the removed portion is replaced and 
welded. In order to hold the piece in place while being welded 
a cast-iron rod may be welded to it to serve as a handle. After 
the weld is finished, this rod is cut off. 

After the cylinder has been welded and cooled off, it should 
be tested to be sure that the weld is entirely tight. "Where it 
is possible, this should be tested with water pressure. If it is 
not possible to do this, the water jacket should be filled with 



ALLOWANCE FOR EXPANSION AND CONTRACTION 167 

keroselie, because kerosene penetrates a crack or a pinhole faster 
than water. 

In case any leaks are found, the metal should be chipped 
out at that point, placed in the fire, and rewelded exactly as 
before. 

The next job, illustrated in Fig. 127, is typical of a large 
class. Work of this kind is usually in cast-iron, though occa- 
sionally of steel, or semi-steel. The piece shown is a cast-iron 
shear arm broken where the section is about 6 or 8 in. thick 
and 16 in. across. In preparing a casting of this size, the break 
is beveled at 60 deg. on each side, using a 12-lb. sledge and a 
handled chisel. It is then lined up and a preheating firebrick 
furnace built around the break, allowing sufficient space for the 
charcoal around the work. Then heat to a bright red well back 
from the break. Two welders should work on a job of this kind. 



^■yf-^^.-Weld here 




Fig. 127. — Broken and Welded Shear Arm. 



each welding about half an hour or less, at a time. A large 
welding head, a long-handled torch and |-in. welding rod are 
used. Two rods should be used, welded end to end. There 
should be plenty of rods and plenty of flux. There should 
also be a good supply of asbestos sheet and a bucket of water. 
The sheet is to keep in the heat and to protect the welders, 
and the water is to cool the torches. After the weld is com- 
pleted on one side, and while the metal is still pretty hot, the 
casting is turned over. The movement will naturally destroy 
the firebrick furnace, which has to be rebuilt again, the casting 
heated up as before, and the weld made. In a job of this kind 
it is necessary to reinforce the weld on both sides. This rein- 
forcing should be about \ in. high. After the welding is all 
done, the piece is heated up to an even red heat all around the 
weld and allowed to cool very slowly. 

In welding in or building up gear teeth, as shown in Fig. 



168 



GAS TORCH AND THERMIT WELDING 



128, it is seldom necessary to preheat. If the gear is a light one, 
say about 3 in. wide and with a rim depth of not over 1 in., 
the job can usually be done without preheating. However, pre- 
heating with some cheap fuel will, on large work, save the more 
expensive gases. In doing a job of this kind the greatest care 
must be taken to start properly. The work should be done so 



■rinhhed Weld\ 




Fig. 128.— Method uf Filling in Gear Teeth. 



as to do away with as much machining as possible. Sometimes 
the tooth may be built up about as shown at A and finished by 
filing or otherwise. At other times it will be necessary to weld 
in on teeth each side of the one to be replaced, as shown at B. 
Again it may be possible to use carbon blocks and fill in as shown 
at C. In using blocks of this kind, care must be taken that there 
is ample room at the bottom for the root of the tooth being 
replaced. 



CHAPTER XI 
WELDING VARIOUS METALS AND THE FLUXES USED 

The first property to be considered in welding various metals 
is the melting point. Gas-torch welding is the joining together 
of two metal parts by fusion at the line of contact and in order 
to secure a perfect weld it is necessary that each part be melted, 
and the molten metal allowed to flow together and harden in 
this state of mixture. 

The approximate melting points and other properties of the 
metals and alloys commonly welded are given in Table XVI, 
taken from "Oxwelding and Cutting." 

When metallic bodies are subjected to an increase in tem- 
perature they expand the rate of this expansion, being closely 
known for each degree of rise in temperature. When the tem- 
perature is lowered a reverse action takes place, the bodies 
contract and the volume and linear dimensions decrease. This 
has been explained to some extent in the previous chapter, and 
examples given to show the effects. Each metal has its own co- 
efficient of expansion, which varies materially for the different 
metals. As seen from the table given, of the metals most com- 
monly welded aluminum expands the most, bronze and brass 
next, then copper, steel, and iron. Aluminum expands almost 
twice as much as iron or steel. 

Conductivity and Oxidation. — The conductivity of a metal 
i?- its property of transmitting heat throughout its mass. This 
property is not the same for all metals, and varies widely. It is 
commonly called thermal conductivity. 

It can be seen that if one metal conducts or transmits the 
heat from the torch flame more rapidly than another, it is 
necessary that allowance be made as to the method of handling 
the job, the size of the torch, and the nature of the preheating 
equipment used. 

In welding metals of high thermal conductivity it is neces- 
sary to use oversize tips — as in the case of copper where the 

169 



170 



GAS TORCH AND THERMIT WELDING 



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WELDING VARIOUS METALS AND FLUXES USED 171 

melting point is low and the conductivity high. However, too 
large a flame is bad, because the operator will not be able to 
correctly place the mass of molten metal. On sheet work the 
proper flame will melt the metal to a width about equal to the 
thickness of the sheet. 

When welding heavy work the operator should be very care- 
ful not to blow a part of the molten metal on to the colder por- 
tions as it will make a defective weld at that point (called an 
"adhesion"). If this should occur, the flame should be played 
over this chilled portion until it is in fusion with the molten 
metal. 

Certain metals oxidize more rapidly than others. Oxidation 
is the reaction produced by the combination of oxygen with a 
metal. The weld may become oxidized by contact with the 
oxygen in the air and by the presence of excess oxygen in the 
welding flame. An oxide has none of the metallic properties 
of the metal from which it is formed. When present in a weld 
it seriously weakens it and it is therefore very necessary that 
it be avoided as far as possible. 

Some oxides are lighter than the metal itself, while others 
are heavier. Consequently, when a metal is reduced to a 
molten condition the oxide will either float on the surface of 
the liquid metal, remain suspended, or tend to sink toward the 
bottom. 

The melting point of oxides is in some cases higher, and in 
others lower, than that of the original metals. This point must 
also be considered in attempting to eliminate oxide from a weld. 

Some metals when molten also have the property of dis- 
solving a portion of the oxide, the extent of this solution being 
dependent upon the metal itself. When this is the case the oxide 
is retained in solution until the metal hardens, in some cases 
separating and producing a weakened weld, in others being 
retained permanently. 

Oxide may be dealt with in two ways. First, by taking 
means to prevent its formation, by the use of a neutral or re- 
ducing flame in the torch, or by the use of various cleaninr^ 
fluxes ; second, by eliminating the oxide after its formation with 
suitable fluxes^ which either dissolve or float it off, or by mechan- 
ically removing it by the manipulation of the welding rod 
or a paddle made for this purpose, 



172 GAS TORCH AND THERMIT WELDING 

The subject of oxidation is one of vital importance to the 
welder, one that he should study thoroughly in order to become 
familiar with all its forms. Oxidation is the cause of a great 
majority of defective welds. 

There are also metals, that, when heated to the melting point, 
have the property of absorbing gases from the flame. "When the 
metals cool, the gases are released. In a great many cases the 
release of the gases occurs at a time when the metal is not 
sufficiently fluid to allow them to pass to the air. Consequently, 
small bubbles or blowholes are incorporated in the weld. Then, 
too, in the welding of various metals the force of the torch flame 
causes the molten metal to flow back away from it. When the 
flame is withdrawn the molten metal returns — similar to the 
action of any other liquid. At such times the return of the 
molten metal may be so rapid that small quantities of the gases 
become entrapped and remain in the weld as blowholes. This 
is a very common occurrence in cast-iron welding. 

In the case of the absorption of the gases by the hot and 
molten metal, the difficulties may be overcome by the use of 
proper protecting and cleaning fluxes and properly prepared 
welding rods. 

In the case of the gases being entrapped by the molten metal, 
this may be overcome by "working out" the gas by means of 
the torch and welding rod. 

Vaporization of Substances. — In the manufacture of 
metals substances are combined in amounts which determine the 
behavior and characteristics of the metal. In iron and steel 
there is a certain amount of carbon, silicon, manganese, phos- 
phorus, sulphur, etc. While these substances may be present 
in only very small quantities, yet their elimination, or presence 
in excess, may materially affect the mechanical properties of the 
metal. 

The high temperature of the welding flame may cause these 
substances to burn out or to volatilize. They can burn or oxidize 
directly in the oxygen of the atmosphere, in excess oxygen in 
the welding flame, or by the reduction of the oxide of the metal 
formed in melting. 

In the working of brasses, bronzes, or an alloy in which 
zinc is present, it is commonly observed that the zinc vaporizes 
and passes off as heavy white fumes in the form of zinc oxide. 



WELDING VARIOUS METALS AND FLUXES USED 173 

It can be seen that when this occurs the zinc content of the 
alloy is materially reduced, and consequently the resultant weld 
will not have the same mechanical and chemical properties as 
the original metal. Special fluxes are provided to prevent this ; 
also, welding rods can be obtained which will either prevent the 
vaporization of the volatile substance or will replace it. 

Separation of Elements. — Alloys are uniform mixtures of 
metals. The fusion of the different elements composing an alloy 
is carried out at a certain fixed temperature. In the welding 
of metals of different kinds, it has been noted that when some 
of these alloys have been heated to the high temperatures pro- 
duced by the welding flame various substances separate or 
segregate and that it is impossible to secure a uniform weld. 

This segregation occurs quite frequently under the torch 
flame and also occurs in the manufacture of the metal. Under 
these conditions the difficulty of welding some alloys can be 
readily seen. 

Welding Various Metals. — With the foregoing facts and 
suggestions in mind we will now take up the various metals 
most frequently welded, and give directions that will apply in 
their special cases. The composition of various fluxes will also 
be given, but it should be remembered that the different acces- 
sory concerns can supply far more satisfactory fluxes than can be 
made in small lots by the individual user, and the welder should, 
where possible, buy the fluxes needed and apply them accord- 
ing to directions. This also applies to welding rods which 
should be bought from reliable concerns for certain specified 
jobs. For emergency work, where the proper rods are not 
available scrap material or wire may be used, but it is not good 
practice. A first-class welder who cares for his work and his 
reputation will use rods of the proper chemical composition for 
the work he has to do. For this purpose he should buy his 
rods from firms of e^ablished reputation, who are not afraid 
to advertise their output. 

Welding Aluminum. — Aluminum parts to be welded may 
be divided into two classes — those made of drawn or rolled 
aluminum and those which are cast. 

Rolled aluminum is usually 98 per cent pure or better, the 
main impurities being silicon and iron. Aluminum as pure as 
this is seldom used for eastings, since its strength is considerably 



174 GAS TORCH AND THERMIT WELDING 

less than that of various alloys. Zinc in amounts ranging from 
5 to 25 per cent, but usually about 10 per cent, was often used 
in the past, but the alloy was so brittle just below solidification 
that a large number of castings were defective owing to shrink- 
age cracks. A copper alloy is now more commonly used, the 
copper content being less than 15 per cent, 7 per cent probably 
being the favorite. This is not so strong at ordinary tempera- 
tures as the zinc alloy, but it does not have such a tendency to 
crack. This makes it much better for welding as well as for 
easting, especially on complicated work. 

Aluminum oxidizes easily in the air, especially at high 
temperatures, and in the latter condition the oxide coating is 
quite thick. This oxide melts at a nuich higher temperature 
(5000 deg. F.) than aluminum (1215 deg. F.) and as the oxide 
is of greater specific gravity (heavier) than molten aluminum, 
it will sink down into the metal when welding unless it is re- 
moved in some way. As the oxide is very persistant to the action 
of any acid or alkali, even at a high temperature, any flux used 
must of necessity be drastic in action and if carelessly used, 
exceedingly injurious to the aluminum weid. On this account 
any flux should be used with caution and any surplus removed 
as soon as possible. 



Table XVII.— Fl 


UXES 


FOR Welding 


Aluminum 






Chemicals 

Sodium Chloride 

Potassium Chloride 

Lithium Chloride 


1 

% 
. 30. 
. 45. 
. 15. 

. 7. 
. 3. 


2 
% 

33.3 
33.3 
33.3 


Formula N 
3 4 

% % 
12.5 IG. 
G2.7 79. 
20.8 . . . 

4 

5. 


UMBERS 

5 • 

% 
17. 
83. 


G 

% 

G.5 
56. 
23.5 

4. 

10. 


7* 

% 
30. 
45. 
15 


Sodium Fluoride 

Potassium Fluoride 


~). 


Sodium Bisulphate 




Potassium Bisulphate 

Sodium Sulphate 

Potassium Sulphate 


3. 


Aluminum Sodium Fluoride. 







* Recommended by the French Laboratories of the Autogenous Weld- 
ing Association. 

A flux is generally used in welding sheet aluminum where 
the puddling method cannot well be employed. More divergence 



WELDING VARIOUS METALS AND FLUXES USED 175 

niu55t be allowed than for iron. Fluxes are usually composed of 
alkaline fluorides, chorides or other combinations as shown in 
Table XVII. However, these and other flux mixtures are only 
given for reference purposes, and it cannot be too strongly 
urged that all welders buy the fluxes used and follow directions 
in each case. 

Where a flux is used in welding aluminum, the edges and 
adjacent surfaces should be well scraped and cleaned as the 
flux is only intended to eliminate the oxide and not grease and 
dirt. In welding heavy sheets the edges should be beveled and 
in light ones the welding will be aided by flanging the edges 
about Vio ii^- 

Aluminum castings are handled a little differently from 
sheets or plates. As previously mentioned castings are of differ- 
ent composition. Since the metal has a low melting point, high 
conductivity, and becomes rather fragile previous to fusion, 
preheating and cooling must be carried out very carefully. The 
average aluminum casting is somewhat complicated in its design, 
hence the necessity of skillfulness in carrying it through the 
preliminary heating period. 

The use of ^ flux on aluminum castings has been abandoned 
by the majority of w^elders. In place of it they break down 
and remove the oxide by means of a paddle, which is also used 
to smooth off the surface of the weld after it is completed. In 
many cases it is an advantage when working on castings, not to 
bevel the edges. 

In most cases aluminum articles should be preheated to some 
extent before welding. In certain cases the playing of the 
secondary flame on the object will be sufficient ; in others a 
more thorough treatment is required, such as charcoal or coke. 
On the regular run of castings it is safest to preheat to about 
500 or 600 deg. F., which on iron would correspond to a low 
red heat. In the case of a broken lug or piece of a flange, it 
is often really dangerous to preheat as it may cause the whole 
piece to collapse or distort. The beginner should also be very 
careful about shifting or turning a hot aluminum casting as it 
may get out of shape or crumble into pieces. Since the metal 
is so apt to crumble when hot it is advisable for the beginner, 
and often the expert, to back up the parts. This may be done 
by molding a backing out of asbestos fiber 2 parts and plaster 



176 GAS TORCH AND THERMIT WELDING 

of paris 1 part, made into a thick paste with water. Have this 
mold about an inch thick and perfectly dry before setting in 
place. Fireclay may also be used in many cases to back up or 
support fragile parts. When the weld is completed the casting 
should be allowed to cool very slowly and evenly. The iron 
puddling rod should not be allowed to get too hot or oxide of 
iron will be formed and scale off, making a defective weld. 

Only a small amount of metal from the welding rod should 
be added at a time and this must be thoroughly stirred or 
"puddled" until a pool is formed that insures perfect fusion 
with the surrounding parts. Use the puddling rod to scrape off 
surplus metal while it is in a pasty condition. The beginner 
will find it a little difficult to manipulate the puddling and the 
welding rods alternately with the same hand but this becomes 
a habit with practice, and many do this by holding them 
between the fingers so that neither needs to be laid down. The 
property of conducting heat is greater in aluminum than in 
iron, but as the melting point is much lower, about the same 
size torch tip is used as for cast iron of corresponding thickness. 

Filling a Large Hole. — The Journal of Acetijle7ie Welding 
says that when the filling of a large hole is required a chill of 
galvanized iron is provided, backing up the hole and welding 
against this when filling the hole with aluminum. Galvanized 
•iron is preferable to any other material, such as tin or iron, 
since it peels away from the aluminum quite readily, and can 
therefore be easily removed after the weld has been completed. 
This is undoubtedly due to the zinc content of the galvanizing 
composition. 

The chief value of the use of the chill is that it causes the 
filler to cool and harden quickly, thereby preventing it from 
contracting after the weld is finished. It also prevents the 
heat of the weld from spreading, which might cause the job 
to crack back. 

The chill causes the added metal to cool almost as fast as 
it is connected to the edge of the break. After the weld has 
been finished and cooled, the chill can be removed by gently 
prying it away from the weld by means of a cold chisel. 

Brass and Bronze. — The composition of brasses and bronzes 
varies so widely that it is not good for a welder to use welding 
rods of the same composition for the general run of repair 



WELDING VARIOUS METALS AND FLUXES USED 177 

work. However, rods of Tobin bronze or manganese bronze 
are very satisfactory for all-round work. Where it is important 
to match the color of the weld with that of the surrounding 
metal it is necessary to use special rods of practically the same 
composition as the welded metal, and also to use extra care with 
the torch. This latter will be better understood when the welder 
knows that several of the alloys such as zinc, tin, etc., used with 
copper to make brass or bronze, volatilize easily and in so doing 
change the character of the metal. These metals should be 
prepared in the same way as any other. They must be so 
placed as to not move during the welding. Fireclay may be 
used to back up pieces in danger of collapse. The end of the 
flame cone should not touch the metal, but should be kept some 
distance above it. If a white smoke rises, or, as in the case of 
bronze, the metal bubbles, remove the flame, as it indicates that 
too much heat is being used and some of the elements are 
passing off in vapor. Do not breathe this vapor as it is poison- 
ous. It is desirable to use a tip about the same size as for cast 
iron. A flux should be used though not too liberally. Calcined 
borax is good. Boracic acid is also good and, if used, may be 
applied by dipping the hot rod into the powder from time to 
time. The principal points to watch are not to heat too hot ; 
do not move the parts until well cooled ; do not use too much flux, 
and be sure to guard against caving in or distortion of the 
work by properly supporting it previous to heating. If the 
metal is porous on cooling it is a sure sign that too high a heat 
was used. 

Cast Iron. — When cast iron is molten it oxidizes very 
rapidly. The oxide which begins to form at a bright red heat, 
melts at a temperature of 2400 to 2450 deg. F. Since the metal 
itself melts at a temperature several hundred degrees below 
this, it can be seen that the oxide will not be melted at the 
same time as the metal. In order to break the oxide down and 
allow the metal to flow together a flux must be used. A properly 
formulated flux will dissolve the oxide and float it to the 
surface, so that it may be removed by scraping the molten 
surface with the end of the welding rod. The welder should 
tap the end against something to free it from oxide before con- 
tinuing to add it to the weld. 

A good flux for use in welding cast iron may be made up of 



178 GAS TORCH AND THERMIT WELDING 

equal parts of earlionatc of soda (washing soda) and bicarbonate 
of soda (baking soda). There is practically no advantage in 
using the pure chemicals in this case as the commercial product, 
which may be obtained at the grocery store, will do as well as 
any. The two sodas should be thoroughly mixed, however, which 
may be done by running them through an old coffee mill several 
times, or thoroughly shaking and sifting in a sieve. The flux 
is applied, as in most other cases, by dipping the hot welding 
rod into it. 

Cast iron is quite fluid M^hen melted. For this reason it 
offers considerable difficulty where vertical or overhead welding 
is attempted. Also its fluidity causes it to entrap gases, dirt, 
and oxide. These may be removed by proper manipulation of 
the torch and welding rod. As the molten iron can be forced 
ahead of the weld very easily, adhesion to the cold metal will 
result, if the welding is not watched carefully. 

The silicon will volatilize to some extent in the molten metal 
and the lowering of the amount of this constituent will seriously 
increase the hardness of the metal. In order to compensate 
for this loss, a welding rod is used that contains from 2.75 per 
cent to 3.5 per cent silicon. The other substances such as sulphur, 
manganese, and phosphorus should be kept within rigid limits. 
The welding rod should be soundly cast, free from dirt, sand, 
scale, rust, etc. 

The welding flame should always be neutral. The flame 
should be applied to the weld at such an angle that the metal 
will not be blown ahead. Inasmuch as the metal is quite fluid 
when molten, the welding is carried on in a series of overlapping 
"pools" or puddles. The welding rod is applied by placing it 
in these pools and playing the flame around it. The welding 
is aided by continually "working" the rod in the weld in order 
that blowholes, dirt, scale, etc., will be forced out. 

The central jet of the flame should never impinge on the 
molten metal. It should be held Vs ii^- to ^Ao i^- from it. 
Occasionally it is necessary to remove a blowhole, in which 
case the hole is burnt out with the flame and then the metal 
is worked over with the welding rod. The working over of a 
weld should be avoided unless it is absolutely necessary. If it 
is necessary to do this the welding rod should be used always, 
for otherwise a portion of the silicon will be lost. 



WELDING VARIOUS METALS AND FLUXES USED 179 

When the wold is finished and it is still hot, the accumula- 
tion of scale, dirt, flux, etc., on the surface should be removed 
by scraping with a coarse file or other tool. This is a superficial 
coating that, when cold, is very hard. 

As soft welds are nearly always desired, the casting should 
bo cooled slowly and evenly. Where the work is complicated 
or of heavy section, it is by all means best to reheat it to a 
good red heat and then allow is to cool slowly. In some cases 
where charcoal has been used it is sufficient to allow the casting 
to cool in the preheating fire, without the additional reheating. 

Cast Iron to Steel. — To weld east iron to steel, east-iron 
rods must be used as the welding material. The steel must be 
heated to the melting point first, as cast iron melts at a lower 
temperature. A very little flux should be used. 

Copper. — Copper usually is produced in an almost pure 
homogeneous form. The impurities are present in small amounts 
and are not affected materially by fusion. Copper is a good 
conductor of heat, and is very tough, ductile, and malleable. 

From these properties it would appear that it is easily 
welded. Unfortunately this is not true. There are few welders 
skilled in the handling of this metal. 

Copper has two very pronounced properties under the weld- 
ing flame. It absorbs gases very readily, notably carbon monoxide 
and hydrogen. These are released when the metal begins to 
solidify, with the result that they remain entrapped, producing 
a porous structure. 

Copper oxidizes very rapidly when undergoing fusion. The 
molten metal has the property of dissolving the oxide thus 
formed. It will take up such large quantities of it that the 
mechanical properties of the weld will be affected. In addition 
to these two peculiarities the tensile strength of copper de- 
creases rapidly as the temperature is raised, particularly from 
500 deg. F. upward. The efifect of temperature is so severe 
that at 900 deg. F. the tensile strength is only 40 per cent of 
that at atmospheric temperatures. 

Because of this weakening under heat, the strains resulting 
from contraction in the weld during cooling must be carefully 
dissipated, otherwise the metal in the weld or adjacent to it 
will fail. 

A neutral flame should always be applied in welding this 



180 GAS TORCH AND THERMIT WELDING 

metal. If an excess of acetylene is used the products of com- 
bustion are richer in those gases which are easily absorbed. If 
an oxidizing flame is used, the weld becomes saturated with the 
oxide. 

A larger size torch tip than the melting point of copper in- 
dicates is used because of the high thermal conductivity. Where 
possible, auxiliary heating, such as air-gas flames and charcoal 
fires, should be employed. This is done not only from the 
standpoint of economy, but it also aids greatly in the success 
of the weld. 

The torch flame should play on the weld in a vertical direc- 
tion. The metal when molten is quite fluid, and for this reason 
if the torch were applied at an angle the metal would be blown 
ahead, producing adhesion. Also, by applying the torch 
vertically the molten metal is protected from the oxygen of the 
atmosphere ])y means of the enveloping flame. 

Copper, if properly prepared and free from grease or dirt, 
does not need a flux. 

The factor that contributes most to the successful welding 
of copper is the use of a properly formulated welding rod. Such 
a rod will overcome, to a great extent, both the absorption of 
gases and the solution of the oxide. It is not considered prac- 
tical to remove the oxide in the weld by means of a flux, because 
it is dissolved in the metal. A welding rod is needed that has 
combined with it a reducing or deoxidizing agent. The reducing 
agent has a greater affinity for oxygen than copper, hence it 
combines with it and brings it to the surface in a fluid form. 
This material acts as a glaze or protecting coating for the molten 
metal beneath it, with the result that it tends to retard the 
absorption of the gases. 

Several materials, when added to a pure copper rod, have 
proved to be beneficial. The most prominent element at this 
time is phosphorus. It should be present in amounts not over 
1.0 per cent ; otherwise the metal will be pasty and the weld 
will be weakened. 

Newly welded copper has only the strength of cast copper, 
but after welding, the grain of the weld and the metal ad.jacent 
can be improved by hammering at a low heat. 

Copper to Steel. — If it is desired to weld copper to steel, 
heat the steel to a welding heat, then place the copper in con- 



WELDING VARIOUS METALS AND FLUXES USED 181 

tact. The metals will then fuse together. Take away the flame 
as soon as the copper flows properly. No flux is needed. 

Lead. — Lead can be readily welded. The process, how- 
ever, is usually known as "lead burning." The gas torch pro- 
vides a means of doing this work quickly and at a low cost. 
Skill in the manipulation of the torch is necessary, particularly 
on vertical seams. A light torch should be used. "When welding 
sheets or plates, proceed as in lead burning by other processes. 

The burned joint on a lead or block tin pipe line is not 
only a neat and permanent joint, but is all lead, and a block 
tin line is all block tin. The joints are fused together with the 
addition of enough metal of the same kind. If, for instance, a 
lead pipe line is to carry acid, the burned joints contain no 
solder which could be attacked by the acid. 

In preparing lead pipe for welding the two pipe ends are 
scraped clean for about an inch back, and are tapered slightly 
at the edges. It is not necessary to drive one pipe into the 
other. The two ends are merely placed in contact and welded 
or "burned" with the addition of more lead to fill up the joint. 
No flux, no grease and no "wiping" of any kind is needed. 

Malleable Iron. — The manufacture of malleable iron has 
made enormous progress during the last few years, and while 
formerly malleable iron was really an unknown quantity and 
might contain different mixtures, from white iron to hard steel, 
in the same casting, a great uniformity is now obtainable by 
adherence to strictly scientific methods. 

The Associated Manufacturers of Malleable Iron has set a 
standard of quality, to which all its members must adhere rigidly 
and castings procured from one of its members may be relied 
on to consist of a uniform and thoroughly high-class product. 

While formerly the welding of malleable iron was considered 
almost impracticable on account of the different structures in one 
and the same casting, it may now be welded with almost a cer- 
tainty of success, if the casting was made in accordance with the 
rules of the association. 

The break on malleable iron is prepared exactly the same 
as for any welding job, cleanliness in this instance being espe- 
cially desirable, since dirt tends to weaken the weld considerably. 
Allowance should be made for the effects of expansion and con- 
traction; malleable iron is less liable to break than cast iron. 



182 GAS TORCH AND THERMIT WELDING 

since it is ductile, but will be distorted unless such provisions 
are made. Use for flux the same powder used for brass — that 
is : borax or a purchased mixture. 

As with cast iron, do not let the end of the cone touch the 
casting, but hold it just a little distance away. Watch the metal 
carefully and as soon as the metal begins to melt, add the filling 
rod, either Norway iron or malleable rod of the same grade as 
the casting. 

However, not all malleable castings are of the high degree 
just described. They were originally white cast iron, very brittle 
and hard. By heat-treatment the carbon content is changed, 
and instead of the brittle casting, it becomes ductile, fairly 
soft and changes to a darker color. Just how far into the body 
of the metal this change penetrates depends upon the size of 
the casting and the length of the heat-treatment, so that a malle- 
able casting, as it is generally called, may be steel on the surface, 
a semi-steel part way through and white cast iron at the core. 

Very small castings sometimes are steel all the way through 
and we may weld them without flux, using Norway iron or 
mild steel as the welding rod. 

In nearly all cases, however, it will be found that the casting, 
if not made to association specifications, is composed of different 
metals — if the break is examined, we can tell this by the differ- 
ent colors. It is obvious that such a casting cannot be welded, 
since it would be extremely difficult to determine just where 
one metal left off and another began. The practice of using 
cast iron as a welding rod on malleable castings is not a good 
one, since the bond is very brittle and in all cases where strength 
is desired we would better use manganese or Tobin bronze — 
in this way securing a brazed joint instead of a welded one, 
of a different color than the casting but with the factor of 
strength a big one. 

Watch the metal carefully and when the spot the flame is 
playing upon reaches a bright red heat, bring the bronze welding 
rod, which has previously picked up some borax, down upon 
this section, being careful that the cone does not come directly 
in contact with the bronze rod. Bronze melts at a lower tem- 
perature than malleable iron and with the iron at a bright red 
heat, and with plenty of flux used, it will be found that the 
bronze attaches itself to the iron. We must not, however melt 



WELDI^IG VARIOUS METALS AND FLUXES USED 183 

any portion of the malleable iron and we must not play the 
cone directly on the iron or on the bronze. 

Monel Metal. — Technically, monel metal is an alloy of nickel 
and copper, containing about 67 per cent nickel, 28 per cent 
copper, and 5 per cent of other elements. This remaining 5 
per cent consists partly of iron from the original ore and partly 
of manganese, silicon, and carbon introduced in the process of 
refining. It contains no zinc or aluminum. The alloy can be 
machined, forged, soldered and welded, both electrically and by 
the gas torch. In the automobile industry it is used for float 
A'ulves in carburetors because it combines hardness with non- 
corrodibility. Borax or boracie acid may be used as a flux. 

Nickel. — Nickel melts at 2600 deg. F. and when melted has 
the property of absorbing large amounts of various gases, espe- 
cially oxygen. The gases so absorbed remain when the metal 
cools, making it very porous. Nickel has also a great affinity 
for sulphur. It is often stated that nickel cannot be welded, 
but this is an error, although it is an extremely difficult metal 
to weld satisfactorily. Anodes used in nickel plating may be 
fused together without flux as the blowholes do not affect the 
conductivity to any appreciable extent. However, where a weld 
is wanted free from blowholes, the nickel pieces should be laid 
on a heavy plate heated bright red or white, and the nickel 
heated to a bright white with the gas torch. The joint should 
then be carefully hammered with a light hammer. Previous to 
heating the nickel should be freed from grease or oil and scraped 
well back from the weld. 

Steel. — Steel welding on a commercial scale should never 
be attempted until after the operator has proved to his own 
satisfaction that the weld is strong by welding together mild 
steel plates -I to :J in., sawing them through the weld to make 
sure that the material is really bonded and testing them by 
bending back and forth in a vise. 

Steel melts at 2500 to 2700 deg. F. When molten it is not 
extremely fluid. At dull red heat it begins to oxidize rapidly. 
The oxide, which melts at a temperature of several hundred 
degrees below that of the metal, remains at the surface and 
can be easily removed. A flux is not necessary, although some 
welders use a little borax. Close attention must be paid to the 
removal of the oxide, however, for its presence is very harmful. 



184 GAS TORCH AND THERMIT WELDING 

It is a common fault to have layers of oxide in the weld, which 
cause a laminated structure that weakens it. 

Steel does not melt rapidly. It gradually comes to fusion, 
confined to small areas. Because of this, the weld is made up 
of small overlapping layers. The strength of the weld depends 
greatly on the thorough bonding of these layers to each other 
and to the beveled edges of the piece being welded. It is a 
common fault to force the metal ahead of the welding area and 
allow it to adhere to the cold sides of the beveled edges. 

A welding rod of over 99 per cent pure iron wire is com- 
monly used. Occasionally a nickel steel rod is used with good 
results on such work as crankshafts. A mild-steel rod is par- 
ticularly satisfactory on steel castings. 

Diameter of 
Thickness of Steel Welding Rod 

1/8 in '. 1/16 in. 

1/4 in. to 3/lG in 1/8 in. 

1/4 in. to 3/8 in 3/16 in. 

1/2 in. and up 1/4 in. 

Steel is very sensitive to the welding flame. An excess of 
acetylene tends to carbonize the metal ; an excess of oxygen 
tends to oxidize. Therefore, a neutral flame should always be 
used and should be tested frequently in order that it be kept 
in proper adjustment. 

Failures due to expansion and contraction are not numerous, 
because of the toughness and strength of the metal. If expan- 
sion and contraction are not properly taken care of, however, 
warping and buckling will surely take place, and internal strains 
will exist in the weld. 

These can be avoided by properly setting up the work and 
with proper preheating methods. 

The strength of a steel weld can be improved by mechanical 
treatment. Hammering is the most common method employed. 
After the welding has been completed, the entire weld should 
be heated to a bright red heat, and. the hammering carried on 
at this temperature. If the hammering is done at a lower 
temperature, the weld will be weakened instead of strengthened. 

The welder should always keep in mind that the higher the 
percentage of carbon in the steel the greater is the danger of 
burning the metal, with its consequent weakening effect. 



WELDING VARIOUS METALS AND FLUXES USED 185 

Steel castings should be handled in a manner similar to cast 
iron. They may be preheated and prepared in the same way. 
C'ast steel as a rule has a percentage of carbon between that in 
mild steel and gray cast iron. As a filler, good results will be 
obtained if cast bars of the same material are used. If not 
available, use vanadium steel or Norway iron filler. 

While little work is done in welding high carbon or hard 
steel, the following instructions are given as a guide to the 
operator in case of necessity. Parts should be prepared for 
welding as for wrought iron or steel. Use a larger tip than for 
the same thickness of mild steel. For filling material where the 
parts are to be hardened, use ordinary drill rod. Drill rod is 
a hard steel which is used by tool manufacturers in the manu- 
facture of drills, reamers, etc. Ordinary mild steel cannot be 
tempered and this is often necessary when high carbon or hard 
steel parts have to be welded. Employ cast-iron flux. Execute 
the weld very rapidly as there is a tendency for the metal to 
burn easily and also to decarbonize; that is, to burn out the 
carbon, leaving the metal in poor condition. A very slight 
excess of acetylene in the welding flame may be advantageous. 

To weld high-speed steel to ordinary machine steel, the end 
of the high-speed steel to be welded must first be heavily coated 
with soft special iron. It can then be welded to ordinary 
machine steel without burning, but it takes an experienced 
Avelder to make a good weld of this kind. 

Special Steels. — There are many special or alloy steels used 
in the metal industry. The operator is often called upon to 
attempt welding on these. Many automobile and locomotive 
parts are made from special high-carbon steels, and often these 
castings or forgings undergo, during manufacture, special heat- 
treatments which are in many cases more or less of a secret 
process. It will be appreciated that welding with a high-tem- 
perature flame must necessarily counteract the effects that were 
produced by the heat-treatments, consequently, to make the 
part efficient it is essential that after welding, the piece be 
properly heat-treated by an operator skilled in such work. The 
services of such a man are rarely available, therefore, the results 
obtained when welding high-carbon alloy steels will be uncertain. 
Fortunately, however, many of the alloy steels used in practice 
are not high carbon and can be welded satisfactorily. 



186 GAS TORCH AND THERMIT WELDING 

Manganese Steel (low carbon) is welded quite readily. 
The manganese acts as a deoxidizing agent ; that is, it counteracts 
the effect of burning the metal. If possible, use a tilling mate- 
rial of the same composition as the part welded. If this cannot 
be obtained use Norway iron. 

Nickel Steel (low carbon) can be welded without difficulty 
in exactly the same way as mild steel, but nickel-steel filling 
rod must be used. 

VoAiadium Steel (low carbon) — This is probably the most 
commonly used steel alloy. Very fortunately it is extremely 
easy to weld, and flows much more readily than ordinary mild 
steel. Weld as mild steel, but use vanadium-steel filler. 

Clirome Steel is in the class of mild or low-carbon steel 
and can be welded readily. "Weld as mild steel. Use a chrome- 
steel filler. Many chrome steels, however, are in the high-carbon 
or hard-steel class. 

Wrought Iron may be easily welded without a flux though 
a little borax or other flux is sometimes advisable. The same 
[general rules apply as for mild steel. 

Galvanized Iron cannot be wielded, since the iron is covered 
with, and to a greater or less extent impregnated with, a lower 
melting metal. 

German Silver, in many cases, is considered unweldable, 
due to its absorption of gases. For practically all commercial 
purposes, it may be bonded, using the same flux as for brass 
and a strip of German silver for the welding rod. Especial 
care must be given to expansion and contraction. 

White Metal Castings used for die molded purposes usually 
are composed of aluminum, tin and zinc in varying proportions, 
but nearly always with the lower melting metals in the larger 
proportion. While the castings have a good deal the same ap- 
pearance as aluminum, they are considerably heavier. They may 
be considered unweldable. 

Silver acts very similar to nickel and should be welded in 
the same way by heating and hammering. However, soldering 
usually answers all purposes. 

Gold welds very easily and the pure melting process is all 
that is needed. 



CHAPTER XII 

EXAMPLES OF WELDING JOBS 

The way a crack to be welded is Vd out or plates are 
beveled, has already been outlined, but it will be well to elaborate 
a little on the methods of doing this work. On steel or wrought 
iron, the beveling may be done with a gas cutting torch. On 




Fig. 129. — An Air Chisel May be Used Either for Grooving or Finishing. 

other metals, such as aluminum or cast iron, the gas cutting 
torch cannot be used, although the metal may be roughly melted 
away. Sometimes the work is of such a nature that the bevel 
may be ground, either with a stationary or a portable electric 
grinding machine. On cast iron, a sledge and a handled chisel 
is often the cheapest and quickest way, and in nearly every 
case it is superior to melting the metal away with a gas torch. 
A very satisfactory beveling tool for all-round shop work, 
is an electric or a pneumatic chisel such as shown in use in 
Fig. 129. This may also be used for taking off surplus metal 
after welding, although a portable electric grinding machine is 
usually preferable. 

187 



188 



GAS TORCH AND THERMIT WELDING 



On work like the propeller blade shown in Fig. 130, the 
slots may be cut with a saw or a milling cutter and the pieces 




Fig. loU. — Propeller Blade Partly Beveled for Welding. 




Pig. 131.— Cylinder Grooved Out for Welding. 

left may be knocked off with a hammer. This bevel might also 
be chipped, ground or melted off, as the occasion or equipment 
at hand demanded or made advisable. 



EXAMPLES OF WELDING JOBS 



189 



An engine cylinder grooved out and ready for preheating 
is shown in Fig. 131. In a case of this kind the grooving may 




Pig. 132. — The Cylinder as Welded. 




Pig. 133. — Broken Automobile Cylinder. 

probably be best done by using a sledge and handled chisel 
for the easily reached parts, and a pneumatic chisel for the 



190 



GAS TORCH AND THERMIT WELDING 



rest. However, this largely depends on the size of the work 
and the judgment of the workman. Fig. 132 shows the cylinder 
welded and ready to be smoothed up. 

A badly broken four-cylinder block is shown in Fig. 133 
and the repair in Fig. 134. The actual cost to weld this job 
was less than five dollars. The method of procedure has been 
previously described. 

In Fig. 135 a welder is shown working on a job while a helper 
is tending to the preheating of another. The method of weld- 
ing through a hole in a large sheet of asbestos not only keeps 
the heat in, Imt protects the operator as well. 

In Fig. 136 is shown a badly broken aluminum upper crank 




Fig. 134.— The Finished Weld. 

case and the repair. Work of this kind often comes to the 
shop that caters to the automobile trade. Another repair of 
interest to the garage man is shown in Fig. 137. The cost of 
putting in a new frame in this 5-ton truck would have been at 
least $600. The weld was finished and guaranteed for $25. 

The welding of a tire for a 15-ton truck wheel, 10 in. wide 
by 2f in. thick, is shown in Fig. 138. The preheating was done 
in a large blacksmith's forge. In this connection, the welder 
must get out of his head a very common idea that preheating is 
only needed to take care of expansion and contraction. It is 
just as valuable in its way, for saving expensive welding gas. 
This is the reason for preheating the large tire, since its shape 
and nature precludes any expansion of contraction troubles 
provided the welder has even ordinary skill. 



EXAMPLES OF WELDING JOBS 



191 




Fig. 135. — Welding and Preheating. 




Fig. 136. — Broken and Repaired Aluminnm Crank Case. 



192 



GAS TORCH AND THERMIT WELDING 



In the example shown in Fig. 139, which is a kettle 5 ft. 
6 in. in diameter and 1^ in. thick, preheating is absolutely 
necessary in order to take care of the expansion and contraction. 
The crack was around the outlet and was 22 in. long. The 



•Ji^* 




Fig. 137. — Welding Frame of 5-Ton Motor Truck. 




Fig. 138.- Preheating and Welding Large Truck Tire. 



welding time was 1 hr. 45 min., in addition to the time it took 
to preheat the kettle the required amount. 

The welding of a 7-in. crankshaft for a 200-hp. internal- 
combustion engine is shown in Fig. 140. The finished weld is 
shown in the insert. The work was finished and the crankshaft 
put back in service inside of 30 hr. The section of the shaft 
added was oversize to permit machining for alignment. Pre- 



EXAMPLES OF WELDING JOBS 



193 



heating in this case saved a considerable amount of welding gas. 
The improvised furnace also made slow cooling possible. 




Fig. 139. — Preheating- and Welding a Large Kettle. 




Fig. 140 Welding a Large Crankshaft. 



Welding Broken Machine Tools. — The planing-machine bed, 
shown in Fig. 141, was cracked through on one side close to the 
housing boss. The job was finished without serious disalign- 



194 



GAS TORCH AND THERMIT WELDING 



ment, but under ordinary circumstances such a repair would not 
be recommended unless means were at hand for refinishing the 
ways and possibly other machined surfaces. As a war-emergency 





Fig. 141. — Weld on Large Planing-Machine Bed. 




Pig. 142. — Broken Punch-Press Frame. 



repair, however, it proved satisfactory. The redemption of a 
similar casting, damaged while still in the rough, might also 
be a money-saving proposition in some cases. 

The punch-press frame shown in Fig. 142, outside of its 



EXAMPLES OF WELDING JOBS 



195 





Fig. 143. — Welded Blowholes in Lathe Pan. 




Fig. 144.— Welded Crack in Lathe Bed.. 




Fig. 145. — Broken Press Frame with Breaks Beveled. 



196 GAS TORCH AND THERMIT WELDING 




Fro. 146.— The Welde<l Press Frame. 




Fig. 147. — Another Welded Press Frame. 



EXAMPLES OF WELDING JOBS 



197 



size, docs not offer any serious welding difficulties, as any possible 
distortion can be taken care of by subsequent adjustment. The 
\velds made in this particular case were 12 in. in thickness, 
and the total time taken to get the press back in service was 
38 hr. 

The saving of defective castings may often prove a very im- 




FiG. 148. — Welding Teeth in a Large Gear. 



portant item to the shop management. In Fig. 143 is shown 
a lathe bed, weighing 900 lb., which came from the foundry 
with sand holes in the pan. These were easily filled up. 

Another lathe bed, sand-cracked where the bed leg joined the 
pan, is shown in Fig. 144. The casting weighed 1750 lb. and 
v,'as saved from being scrapped by 27 min. of welding work. 

A broken frame of a punch press is shown in Fig. 145. 



198 



GAS TORCH AND THERMIT WELDING 



This frame was 4^ ft. high, 2^ ft. wide and from f to 1} in. 
thick. It weighed 500 lb. The welder's time on the work was 8J 
hr. ; helper's time, 8i. ; oxygen used, 425 cu.ft. ; acetylene used, 
327 cu.ft. ; cast-iron filler, 4 lb. ; preheating, 4 hr. with gas at 
a cost of 60 cents. The total cost to-day can be computed by 
taking the present cost of labor and supplies and multiplying 




Fig. 149. — A Large Pulley Welded in Twelve Places. 

by the figures given. The finished job is shown in Fig. 146. 
An Oxwcld torch was used. 

A much simpler, and in fact almost an ideal piece to weld, 
is shown in Fig. 147. The frame is 12 X 12 in. at the break. 

Ten teeth were broken out of the gear shown in Fig. 148. 
The gear was 8 ft. in diameter and the teeth 10 in. long, 3 in, 
high and 3 in. thick. It is seldom necessary to preheat in a 
case of this kind except to save gas, but care should be taken to 
keep the heat in as much as possible. 



EXAMPLES OF WELDING JOBS 



199 



A practical man would at once question the advisability of 
trying to repair a pulley broken as indicated in Fig. 149. This 
pulley is 7 ft. in diameter and was completely welded in 12 
places as indicated, and ready for service in 48 hr. The work 
was done so well that the rim ran practically true, except for 
about :^-in. side play. This particular case was a war-emergency 
job, but sometimes such a repair job is of vital importance at 




Fig. 150. — A Welded Locomotive Frame. 



the present time, for such a pulley can seldom be replaced by 
a new one without considerable delay. 

In many instances broken locomotive frames may be quickly 
repaired with the gas torch without dismantling, and the engine 
put back into service in a short time. Such a repair is shown 
in Fig. 150. This job took altogether less than 24 hr. from 
the time the engine was run in until it was on the road again. 



200 



GAS TORCH AND THERMIT WELDING 



PREPARATION FOR LOCOMOTIVE FRAME WELDING 

Writing in the Welding Engineer, G. M. Calmbach, super- 
intendent of welding for The K. C. Southern Railway, gives 
directions for the preparation of a locomotive frame for 
welding. 

"Tram frame and check with opposite slide, then tram over 
break locating permanent points by which the expansion will 
be governed. See Fig. 151 for expansion. 

L/N£ UP FRAME AND TRAm 
.^ BEFORE CUTTING AWAV 
^^ THEN eXPAND ASSHOWM 

V BY "/*"— "S ' 




y^ io-^ 'Reinforcement 




note: ^ 

at breaks marked "a" i*! 

ALLOW /i "f6R CONTRACTION 

AT THOSE MARKED ' B' 
AUOW ^//6' 

Fig. 151. — Locomotive Frame Welding. 



"Frame should be cut out from both sides as shown, then 
surface to be chipped absolutely clean preparatory to welding. 

"Weight of engine should be taken off of frame and jacks 
placed under legs of jaws on either side of weld. 

"Where welds are to be made in any part of jaw binder 
should be in place if possible. 

"As an expedient to start the weld |-in. plate should be 
tacked to lower side of frame on which a foundation can be made 
to start the weld, welding plate solid to frame and also welding 
edges of plate, this plate to extend out on both sides of frame 
the thickness of reinforce. 

"Two operators should be always employed, that is, one on 
each side of frame. After weld reaches the thickness of 2 in. 



EXAMPLES OF WELDING JOBS 



201 



it should be hammered, this hammering to continue until weld 
is finished. 

"It is important that at no time during progress of weld that 
any part of weld be less than a red heat, that is to say, operators 
should keep finished part of weld red hot at all times and 
when weld is finished, the entire weld should be brought up to 
en even heat before jacks are removed." 

The gas torch is almost as useful for welding around a 
shipyard as it is in a railroad shop. Fig. 152 shows a 4-ton 
forged-steel rudder frame broken as indicated by the arrows. 




Tig. 152. — Rudder Frame Eeady for Welding. 

The break has already been beveled out for welding. The cost 
was about $60 as compared with about $1400 for a new frame, 
and the time taken was a fraction of what would have been 
required to obtain a new one. 



COOLING DEVICES 

On many large jobs, where considerable preheating has to 
be done, the discomfort of the welder may cause defective welds 
or even complete failure. Sometimes asbestos screens can be 
used; at other times it is necessary to shift welders every few 
minutes. Two suggestions that may be helpful in certain cases 
are here given. H. Howard suggests the use of an "air screen" 
as outlined in Fig. 153. A row of small holes is drilled in 



202 



GAS TORCH AND THERMIT WELDING 



a pipe of convenient size to attach to the air hose. The other 
end of the pipe is closed. This contrivance is placed across 
under the torch and held by a clamp or a weight in such a 
jjosition that a curtain of swiftly moving air passes between 
the hot casting and the operator. The device affords protec- 
tion from the heat and does not interfere with the manipulation 
of the torch or obstruct the view of the operator. 




Fig. 153. — Cooler for Use in Welding. 

Acetylene- - . 




I Oxygen-' 



'&-Ajr 



Fig. 154. — Another Cooling Device. 

This device, while useful for certain jobs, has disadvantages, 
as it does not follow the movements of the operator. J. R. 
Gumming suggests the one shown in Fig. 154. A ^-m. air pipe 
is fastened to the gas torch by a light iron clip. The air pipe 
is connected by a light hose to the air supply. By the exercise 
of a little ingenuity in making this attachment, an operator 
can keep his hands and face reasonably cool on many jobs that 
would otherwise make him exceedingly uncomfortable. 



EXAMPLES OF WELDING JOBS 



203 



Tlie -way to prepare seams in boiler and tank welds has 
already been shown, and only one example will be given. Fig. 
155 shows a tank which in use has to stand a pressure of from 
200 to 300 lb. It is 4 ft. in diameter and 5 ft. long. The 
shell is made of g-in. plate and the dished bottom of f-in. 
plate. The longitudinal seam is welded, and the bottom welded 
to the shell in 6 hr., at less than the cost of riveting, and no 
caulking is needed. 

There have been extensive tests on the strength of gas-torch 




Fig. 155.— a Welded Tank. 



welds on ])oiler plate and the following results are given by the 
Oxwcld Company: 



No. of 

Specimen Dimensions 

1 1.522 X 0.393 

2 1 ."A X 0.380 



Area in 


Brealdng 


Stress per 


Efficiency 


Sq.In. 


Load 


Sq.In. 


of Weld 


0.598 


25,130 


42,000 


84% 


0..592 


23.000 


42,800 


8t).G7o 



This efficiency is figured on the basis of 50,000 lb. per square 
inch as the ultimate tensile strength of the material, elongation 
Vic of an inch in 2 in. as welded, or about 9.3 per cent. 

The average of a number of similar tests taken at random 
from a considerable list was 79 per cent. 

A comparison between the cost of welding and riveting 
shows that up to certain thicknesses of plate, notably | in., 
welding is cheaper per lineal foot than riveting. On heavier 



204 



GAS TORCH AND THERMIT WELDING 



material than this, however, the cost is usually about the same 
as good riveting practice. 

The speed and cost per foot of welding with an Oxweld 
torch for different thicknesses of plate are: 



Thickness of 


Lin. Ft. 1 


)er 


Cost per 


Metal, In. 


Hour Welded 


Foot 


1/8 


20 




$0.04 


3/16 


15 




.06 


1/4 


10 




.09 


3/8 


6.5 




.23 


1/2 


6.0 




.27 


5/8 


4.5 




.35 


3/4 


3.0 




.60 


1 


2.0 




L20 



This table is compiled from results obtained from actual 
shop practice. The price of oxygen is figured at 2 cents per 
cubic foot, acetylene at 1 cent and labor at 30 cents per hour. 
Other gas and labor costs can readily be substituted to meet 
any local conditions. 

RAIL BONDING 

Electric rail bonding, such as shown in Fig. 156, is very 
easily done with the gas torch. Fig. 157 shows a welder at 




Fig. 156. — Electric Bails aud Welded on Bond. 

work on a job of this kind. The apparatus used is mounted 
on a spe(aal truck so as to be easily moved along the rails from, 
one joint to the next requiring bonding. 



EXAMPLES OF WELDING JOBS 



205 



The filling up of blowholes, cold shuts and cracks in castings 
of various kinds is well known to most foundry workers, but 
the building up of worn or over-machined parts is not so 
familiar to the general run of mechanics. 

A good example of the reclaiming of an expensive casting 
worn in service is shown in Fig. 158. This is the casing of 
a circulating pump. A strip of metal about 3 in. wide and f 
in. thick had to be built up around the entire inside edge of 
the casting. The Avork was done by two operators working as 




Fig. 157.— Bond Welding Outfit in Use. 



shown. The added metal was then ground smooth enough for 
the purpose and the casing put back in service. 

Building up worn pods on steel-mill rolls is shown in Fig. 
159. A rough brick furnace is built around the end to be 
welded and charcoal used to heat up the work to save gas. 
The welding in this case was done with thermalene, but any 
good gas outfit may be used with good results. 

The large chain belt links. Fig. 160, were cut undersize on 
the corners and were reclaimed by building up as shown. 

Aluminum automobile transmission or other castings often 
come through slightly defective. To recast them would mean 
a duplication of costs in cores, molds, handling and turning. 



206 



GAS TORCH AND THERMIT WELDING 




Fw. 158. — Building Up Wuru i'aita of Lixiga Pump. 




Fig. 159.— Welding Pods on Steel-Mill Rolls. 



EXAMPLES OF WELDING JOBS 



207 




Fig. 160. — Building Up Over-Machined Chain Links. 




Fig. 161. — Filling Blowholes in an Aluminum Gear Case. 



208 



GAS TORCH AND THERMIT WELDING 



which would mean a considerable loss. They are welded — the 
holes filled with similar metal from a "filler-rod" as shown 
in Fig. 161 — at a cost of but a few cents each and they pass 
inspection as being as good as perfect castings. 

Through error four cast-brass U-plates for rudder frames, 
Fig. 162, weighing 1000 lb. each, were made 6 in. too long. 

To repour these plates would have held up some important 





















, * 


V #3fti ,^_._ 


1 


■¥A 










^E 


k- 










1 


kf ■* * 










^ 












H« 



Fig. 162. — Brass Eiidder Frame Salvaged by Welding. 

work and the expense, including change of pattern, would have 
been very high. The mistake was quickly and economically 
corrected by cutting 6 in. out of each as shown by the illus- 
tration and welding the frames together again. 



A REMARKABLE CYLINDER WELDING JOB 

Writing in the American Macliinist, Jan. 8, 1920, L. M. 
Malcher, superintendent of the Chicago shop of the Oxweld 
Acetylene Co., says: One of the 5000-hp. Allis-Chalmers twin 
tandem compound reversing steel rolling mill engines at the 
Farrell works of the Carnegie Steel Co., Farrell, Penn., that 
had been doing its full share in helping to win the war 
broke down two weeks after the signing of the armistice. In 
the accident, besides other parts, the left-hand low-pressure 



EXAMPLES OF WELDING JOBS 209 

steam cylinder, Fig. 163, 70 in. inside diameter, was badly 
fractured, as a result of the breaking of a connecting-rod at the 
moment of reversal. 

It would have taken at least three to three and one-half 
months to obtain a new cylinder, in case the broken one could 
not be repaired in a shorter time ; besides throwing 360 men out 
of employment. The broken cylinder was of such size and the 
damage done was of such character that a decision whether 




f IG. 163. — Wrecked Low-Pressure Cylinder. 

The seven cracks ranged from 1 fa § ft. in length and 24 to 3g in. in depth and 
are shown V-grooved by chipping preparatory to welding. 

the cylinder was to be renewed or repaired involved a risk 
on the part of the management. 

Although it was decided that consideration of expense be- 
tween the cost of purchasing a new cylinder and the repairing 
of the old one were of secondary importance, the cost of repair- 
ing was estimated to be about one-third that of a new cylinder. 

Decide to Make Repair. — The officials of the company after 
having made a careful investigation quickly decided in favor 
of oxy-acetylene welding. They called upon the job welding 
shop of the Oxweld Acetylene Co., Chicago, 111., to meet the 



210 



GAS TORCH AND THERMIT WELDING 



emergency. Three expert welders, accompanied by all necessary 
equipment, went immediately to Farrell and completed the job 
under the direction of the writer. 

The fractures of the cylinders were what are commonly 
known as "end breaks"; that is, the cracks are on the extreme 




Fig. 164. — Preheating Crack in Low-Pressine Cylinder by Means of 

Charcoal Fire. 

outside end of the casting. As a rule it is only necessary to 
preheat the casting locally (Fig. 164), and while the heat will 
radiate into the casting to some extent, the intensity is not enough 
to harm any portion by warping or shrinkage. The total time 
consumed in repairing the low-pressure cylinder, including 
chipping, preheating and welding, was 72 hours. 

While dismantling the engine a fracture was discovered in 



EXAMPLES OF WELDING JOBS 



211 



the right-hand, 42-in. diameter, high pressure cylinder. This 
fracture also was repaired in about 18 hours. It took just 
seven days from the time the order was placed to complete the 
entire job. 




Fig. 165. — Welding the Low-Pressure Cylinder. 
Asbestos paper was used to protect workers and retain heat from preheating fire. 
Note the extra long torches and rods required for the long cracks. 

The data covering this work are given in detail in the accom- 
panying table. 



Low-Pressure Iligli-I'ressure 

Steam Cylinder Steuni Cylinder 

Cylinder bore 5 ft. 10 in. 3 ft. 6 in. 

Stroke 4 ft. 6 in. 4 ft. 6 in. 

Weight of cylinder 13 tons. n tons 

Thickness of iron casting 2| to 31 in. 3i to 6 in. 

Total length of weld 22 ft. 2 in. 4 ft. 6 in. 

I'reparing and preheating casting.. 27 hr. 9 J hr. 

Welding casting 45 hr. 8| hr. 

Oxygen consumed 2850 cu.ft. 650 cu.ft. 

Acetylene consumed 2845 cu.ft. 650 cu.ft. 

Cast iron welding rods 390 lb. 110 lb. 

Flux '. 25 lb. 10 lb. . 

Number of welders 3 3 

Period of welding shifts 10 and 30 min. 10 and 30 min. 



212 



GAS TORCH AND THERMIT WELDING 




Fig. 166. — Welding of Low-Pressure Cylinder Completed. 




Fig. 167. — Flange Welded on the 5-Ton High-Pressure Cylinder. 
Weld 4J ft. long, 3i to 6 in. deep. 



EXAMPLES OF WELDING JOBS 213 

While welding inside of the cylinder eastings, as shown in 
Fig. 165, the men relieved one another every 10 min. because 
of the extreme heat deflected back on them during the welding 
o])eration. On the outside welding, however, the heat was not 
so intense and the men relieved one another every 30 min. 

After the engine cylinders were machined, it was almost im- 
possible to determine where the cracks had occurred, as can 
be seen from Figs. 166 and 167. 

The total cost of the complete repair represented but a 
small fraction of the replacement co.st, but even this saving 
is insignificant when compared with the disorganization which 
would have resulted from the laying oft' of a large body of 
trained workmen and with the enormous loss that would have 
been entailed in a stoppage of production. 

WELDING HIGH SPEED TOOL TIPS TO LOW CARBON SHANKS 

The welding of tips of high speed steel to low carbon shanks 
i.i perfectly feasible and several methods of performing this work 
are in successful use. As a means of lowering costs of produc- 
tion the process commends itself to manufacturers, engineers 
and plant managers, says the Welding Engineer. 

The principal reasons for the failures of the welder who 
attempts this class of work is because of his ignorance of the 
class of steel he is attempting to weld and because of a lack of 
practice. Therefore, it is plain that to acquire skill in the 
welding of high speed tips to low carbon steel the operator 
must not be discouraged by a few failures, but must master the 
problem by study and practice. 

So far as the low carbon steel used as shanks is concerned, 
this steel may be roughly divided into three general classes : 
Cold drawn, open hearth and Bessemer. The high carbon steels 
are more numerous and many metals enter into their com- 
position. No doubt the bulk of the welder's failures would 
be eliminated if he had a perfect understanding of the varied 
and intricate analysis of many of the high carbon steels of the 
day. He often fails to appreciate that, controlling a heat of 
6300 deg. F. he plays it unnecessarily long on a steel which 
melts at from 1800 deg. to 2500 deg. F., which results in burning 
the metal. In the mills where such steel is made, should a furnace 



214 GAS TORCH AND THERMIT WELDING 

be allowed to reach such a temperature, an entire heat would 
be destroyed. 

The first step in welding high speed tips to low carbon 
shanks is the preparation of the shank, which is beveled as shown 
in Fig. 168. The tip of high speed steel is not to be beveled. 
The shank and tip should then be sand blasted, after which the 
sand dust should be wiped off the surfaces to be welded. It is 
good practice to preheat both the shanks and the tip to a cherry 
red (about 1375 deg. F.). Then build up ^ in. of metal on 
the surface of the shank that is to be welded, and also on the 
surface of the tip which is to be welded, using a V^g or i in. 
nickel steel welding rod and a flux such as is used for cast iron. 




Fig. 168.— One Method of Preparing the Shank and Tip. 

Then place the tip in the position it is to occupy and tack it 
and weld one side with a nickel steel rod. A flux is not neces- 
sary. Turn the tool over and weld the other side. Both sides 
should be welded from the end, progressing toward the heavy 
portion of the shank. 

The reason for this is as follows : The low carbon steel shank 
vv^ill absorb heat more rapidly than the tip. As the flame is 
progressing towards the shank the tip is therefore subjected 
to as little heat as possible, and the shank will absorb the 
most of it. 

Now set the tool up and weld the sides and top, where the 
high speed steel joins the low carbon shank. In order to reduce 
as much as possible the interval between the beginning and the 



EXAMPLES OF WELDING JOBS 215 

ending of the welding operations a sufficiently large tip should 
be used and care should be taken that the tlame is not played 
on one spot too long, or the metal will be burned. 

It will be noted that a nickel steel welding rod is recom- 
mended, although in justice to some very capable welders it 
may be said that in certain shops both Norway or Swedish iron 
rods and Vanadium steel is being used. The author believes, 
however, that the results attained justify the statement that 
nickel steel rods are preferable. 

Many welders overlook the fact that the physical properties 
of high speed steel and ordinary tool steel are so different that 
strains are set up by welding. Therefore it is essential that the 
welded tools be heat treated before cooling from a welding 
operation. When possible a furnace should be used for this 
purpose. If the life of the tool is of but short duration, it is 
sufficient to bury it in lime or asbestos as soon as the welding 
operation is completed. Another good method is to place the 
tool on end and in a tank which contains any good mineral oil. 
This tempering or hardening process should take place directly 
after the welding operation and before the tool cools. 

As was pointed out at the beginning of this article, in the 
welding of high speed tips to low carbon shanks, much depends 
on the operator. In ordinary tool-room work when a difficult 
or intricate tool or jig has to be made, the foreman selects one 
of his best men to do the work. In the case of failure, the 
human element is blamed. With the oxy-acetylene process, how- 
ever, the blame is too frequently placed on the process or the 
apparatus. Too often the verdict is, "No good for that kind 
of work." This snap judgment is usually due to a lack of 
loiowledge on the part of both the welders and their foremen. 
In handling work of such a special character as welding tools 
it should be understood that the welder should, if he is not 
already experienced in that work, be given an opportunity to 
study and practice and his first failures should neither condemn 
him or the process. The results to be derived from patience 
will justify the expense of the welder's training. 

G. A. Hastings, in the American Machinist, says : ' ' Our 
high-speed steel scraps consisted of all sorts of short ends. 
Owing to the high price of steel we decided to try oxy-acetylene 
welding to utilize the ends on a mild-steel shank. We pre- 



216 



GAS TORCH AND THERMIT WELDING 



pared for the weld, as shown in Fig. 169, and have turned 
out lathe, shaper and planer tools that give entire satisfaction. 
The high-speed points were cut with a hot set and ground 
to the proper shape, the welding edges being beveled toward 
the center at about 45 deg. The shank was made in the same 
way and the weld made with an ordinary steel-welding rod. 
We figured that making the weld at an angle of 45 deg. from 



ti,gh -speed 
5 fee/ 




Fig 169 — -Another Method of Preparing the Shank and Tip. 

the base would give the welded j^oint a better support from the 
end of the shank and reduce the stresses at the weld. 

The first tool made cost about 35c. excluding the somewhat 
doubtful value of the high-speed scrap used for the point. 
Later tools, of course, cost less. 

Regarding Presto-0-Lite Co. practice, A. F. Brennan says: 
''The weld is made in the following manner: Both the machine 



bevel from bofh Sides 
for yielding 




^-Machine Sfeel ..High-Speed Steel 

Fig. 170— Frest-O-Lite Tool Wekling Practice. 



steel and the high-speed steel are beveled from two sides by 
grinding, as shown in Fig. 170, It is important that this 
bevel extend clear to the center of the piece and that the 
angle be a generous one — at least 90 deg. It has been found 
that a nickel-steel welding rod made of a low-carbon steel 
containing about 3 per cent nickel gives the best ,results, and 
no flux is used. 

"The weld should be executed just as though both pieces were 
of machine steel, except that greater care should be taken to 



EXAMPLES OF WELDING JOBS 



217 



insure the penetration clear to the center of the parts being 
welded; and it will probably be found necessary to "puddle" 
or "work" the molten metal with the filling rod, as some 
grades of high-speed steel do not flow readily under the torch. 
Wherever possible, the weld should be built up or reinforced, 
although in some cases this is impossible, as when the welded 
portion is to be used inside the tool holder. In such cases the 

Righ+-hand Rgughincj h* 

Tool Prepared ^(High-. 

for Weld ing 



Offseionofhef 

side for /eff- 

kand fool 




Fig. 17L — Details of Tools with Oxy-acetylene-welded Points. 



weld has to be ground off level. After the weld is completed, 
the tool can be ground and tempered in the usual manner. 

' ' A tool 1 X 1 ill. can be welded, if properly beveled, in about 
10 min. with a No. 6 tip. The oxygen consumption for this 
operation is about 5 cu.ft., and the acetylene consumption is 
approximately the same. On this basis the labor costs are 5c., 
acetylene and oxygen 10c. each, and filling material 5c. 

"I have never welded on any points of high-speed steel less 



218 GAS TORCH AND THERMIT WELDING 

than about an inch and a half long; but if the material is 
properly handled, I believe that this length could be reduced. 

"When it is remembered that the price of high-speed steel 
has risen greatly, the practice is worth considering. 

"Further, there are oftentimes short ends of high-speed steel 
that are not long enough for use. They are usually sold for 
scrap, but may be used to advantage by this method." 

The practice of the Root & Vandervoort Engineering Co., 
East Moline, 111., is as follows: The mild-steel shank and high- 
speed steel point or bit are shaped as shown at A and B, Fig. 
171. The details give the proportions of one kind of round- 
nose turning tool for roughing cuts, and for both right-hand 
and left-hand setting. The shanks and points may be forged 
or machined to the shapes given, but in the case of forgings 
the angular surfaces must be ground to free them from scale. 

When welding, the tool is laid on its side and the parts 
blocked up so that they are in proper relation to each other. 
They are then welded, using an oxy-acetylene welding outfit, with 
a torch having a tip, giving a flame about f in. long. Round 
Norway iron V^ in. in diameter is used for filling, and care 
if-; taken to prevent the flame from directly touching the high- 
speed steel point. The operator keeps the welding rod between 
the flame and the piece of high-speed steel. The angular grooves 
on the sides of the tool, as shown at B, are filled up a little 
more than flush and most careful attention is given to see that 
a first-class weld is made. 

After the tool is welded, no hammering of any kind is done 
on it, and all shaping is done by grinding. After rough grind- 
ing, the tool is hardened in the usual manner, and then after 
finish grinding, it is ready for use. 

The finished shape and dimensions of a right-hand roughing 
tool made by this method are shown at C, and a similar left- 
hand tool at D. 

In another article, Herbert V. Ludwick writes: Owing to 
the high cost of high-speed steel, the practice of welding high- 
speed tips to machine-steel shanks is of interest to manufacturers. 
Welding a high-speed steel tip to a machine-steel body for 
cutting off tools for automatic machinery has been more or less 
a difficult problem, owing to the shock the weld has to stand 
from the constant chatter of the stock against the tool. 



EXAMPLES OF WELDING JOBS 



219 



Take two pieces of high-speed steel A, Fig. 172, f in. square 
by 2 in. long, and grind a 4-in. radius on the end of each. A 
rough machine-steel body is milled at both ends as illustrated 
at B. The parts are assembled and put in the jig C, which is 




Assembly showing Blade 
c'dmped in Jig C 



^f">i 



^f^;--::^' 



pt/>|ri < Afh 



Z2 HDjQb^ mr^ ft,- 

Block for Holding Blade "^a ^" U I I L 



(mcmtSTm) 



K"R:-^J 


\ \ctR 




1 



.>l^"k ->)l"k '" 

I j/ri S\rap(WCm£smL) 



16 Threads per 
'Ipch.U.S.Std 
Right Hand 



Contour of Blade after Welding 
|< - -- S- >l >\ VQZ50" 



y 

Rough 
grind 



t 



s"..^ 



2L. 



Contour of finished Blade 



Clamp (COLO-ROLUOSTUL) 



B 



Fig. 172. — Jig for Welding High-speed Steel Tip to Machine-steel Body. 

made from two pieces of f X f-in. machine steel D and E. 
They are fastened with two clamps F, made of flat steel held 
by h- or f-in. U-bolts G. Wing nuts should be used if at all 
possible, as they are easily and quickly adjusted. 



220 GAS TORCH AND THERMIT WELDING 

The reason for using the jig is that when the flame of the 
torch is directed on the places to be welded it heats the tips 
and the body of the blade very quickly and causes the steel in 
the blade to expand before the jig has time to get very hot. 
These two bodies, when heated until they run at the weld, are 
forced together by their expansion, resulting in a better weld. 

The work should be removed from the jig quickly and placed 
in powdered lime or bar sand, to prevent chilling and the 
formation of hard brittle spots in the weld, which are difficult 
to machine even after the regular annealing process. 



CHAPTER XIII 

WELDING JIGS AND FIXTURES 

Where a welding shop does a general line of work which 
includes everything that comes, there should be an ample assort- 
ment of drilled straps, angle irons, bolts, V-blocks, clamps, 




Fig. 173.— Table for Holding Welding Work. 

plates and the like. Good supplies of fireclay and plaster of 
paris are also very desirable for supporting or holding irregular 
work that is apt to collapse or get out of line. Many times, 
a table such as sho^vn in Fig. 173 will answer for certain jobs. 

221 



222 



GAS TOPCH AND THERMIT WELDING 




Fig. 174.— Holding T'ipc lor Wi-lding, 




Fig. 175.— V-Blocks for Holding Shafts. 



WELDING JIGS AND FIXTURES 



223 



The top of this table is made of a "grated" slab of cast iron 
supported on a welded angle- and strap-iron frame. The slots 
provide means for the insertion of clamping bolts. A table 
similar to this can easily be made in any welding shop. 

Pipe welding is a very common and re-occurring job in most 
shops. Some rig up V-blocks, rollers or other devices, but the 
method shown in Fig. 174 is very good. It is simply a piece 
of angle iron placed on iron horses as illustrated. The ends 
of the pipe to be welded are cut square and the outside ground 
back for about two or three inches to remove rusty scale and 
dirt. On long pieces of pipe the grinding may be done with a 
portable electric grinding machine while the end of the pipe 
sticks out a foot or so from the end of the channel iron. The 
pipe in this case remains still and the grinding machine is 
moved around it as the operator stands in front of the pipe end. 



/Weld here 




Fig. 176.— Jig for Hokling Crankshafts. 



The short or easily handled pieces of pipe may be ground on 
a stationary grinding machine. 

The best part about using an angle iron is that the pieces 
of pipe to be welded are held in line while being tacked together. 
On ordinary sizes the welder will have no difficulty in turning 
the pipe as he welds. On heavy pipe some form of rollers will 
be found very convenient. 

A very simple way to weld straight shafts is shown in Fig. 
175. Here the shaft simply rests on high V-blocks which keep 
il in line but do not interfere with expansion or contraction. 

A jig for holding a motor crankshaft broken in the shaft 
is shown in Fig. 176. The main part of the crankshaft is 
clamped to three V-blocks. The bases of these "V-blocks are 
grooved to fit over a tongue in the baseplate, so that they may 
be slid along in order to adjust them to various sizes of crank- 
shafts, and yet keep them in line. The V-block holding the 



224 GAS TORCH AND THERMIT WELDING 




Pig. 177. — An Adjustable Ciankshaft Jig. 




Fig. 178. — Welding a Broken Web in the Jig. 



WELDING JIGS AND FIXTURES 



225 



short pieco to be welded on is made in the same way, but the 
piece should not be clamped in solidly but should be so held 
that it can move lengthwise. This may be done by clamping 
loosely or else haying the V-block free to move along the tongue 
The rigid clamping of all parts would cause distortion and 
springing of the crankshaft. 

The device shown in Fig. 177 is in use in the Oxweld shop. 




rtnllllilUlllM 
FiG. 179. — Aliimimim Crankcase Stiffened by Angle Iron. 




Fig. 180. — Angle Iron Applied to Another Job. 



Four V-bloeks are made to slide on bars, as illustrated, and 
may be clamped wherever desired. Each V-block carries its 
own clamping screw for holding the work. For ordinary shaft 
welding the table may be used in a horizontal position, as 
shown, but for welding breaks in webs the table may be tilted 
as shown in Fig. 178. This illustration also shows the use of 
a coal-gas and air torch to heat the work while the welder is 
using the welding torch. 



226 GAS TORCH AND THERMIT WELDING 




Fig. 181. — Crankcase with Angle Iron and Bearing Mandrels in Place. 



' ■ ' ^^'. 












1 








%J^Km^ \\ 1 


V 




K 




jUmi^^ '-iiiiiiii^ff 


i 




w' 




jBt/^ml^B^^^^^^^BB^^^BMSM 


1 


i 




d 


B^ ' ""^MHirf"^ "^' - ■ 7*" 


^ 


fc#**'* 


^^^^< 




I^^^^^^I^BSMI^^^'^^^^S 


12 




g 



Fig. iSi;. — Motoreycie Manifold Welding Jig. 



WELDING JIGS AND FIXTURES 



227 



Crank eases or other automobile parts may be held in order 
to prevent distortion as much as possible, as shown in Fig. 179. 
In this case angle irons and short bolts with wingnuts are all 
that are needed. The patch to be welded in is shown tacked 
in place at A. ' Another application is shown in Fig. 180. The 
patch B has been tacked in two places ready for welding. 




Fig. 183.— a Welded Motorcycle Manifold. 




Fig. 184. — A Sheet-Metal Roller Welding Jig. 

In Fig. 181 both angle irons and mandrels are used in the 
bearings. These mandrels may be solid or of pipe to fit the 
bearings. Sometimes, where it is necessary to keep the bearings 
cool, a pipe with elbows screwed on each end may be clamped 
in. With the ends of the elbows up, the pipe may be filled with 
water. 

The Henderson Motorcycle Co. uses the jig shown in Fig. 



228 



GAS TORCH AND THERMIT WELDING 




Fig. 185. — A Welded Conveyor Roller. 






Pj(5. 186.— Larffe Sheet-Metal Cylinder Welding Jig. 



WELDING JIGS AND FIXTURES 



229 



182 to hold the parts of their exhaust manifolds while welding. 
The construction and operations are obvious. A welded mani- 
fold is shown in Fig. 183. 

Holding Sheet-Metal Cylinders. — A very simple welding 
jig is shown in Fig. 181. This consists of four castings: the 




Fig. 187. — Apparatus for Welding Ends in Cylinder or Tanks. 



base, two side pieces and the hollow mandrel. The cylinders 
welded are 6 in. in diameter and 8^ in. long, made of ^-in. 
plate. They are used to make the conveyor roller shown in 
Fig. 185. The seam is welded in three minutes. 

Another cylinder welding jig is shown in Fig. 186. This 
is in use in the Thermalene shop. The edges of the cylinder 



230 



GAS TORCH AND THERMIT WELDING 




WELDING JIGS AND FIXTURES 231 

to be welded arc held up to the V-channel from underneath by 
a bar locked in place by bolts and large wingnuts. 

The speed for welding sheet metal will of course vary widely, 
but the following approximate results on sheet iron and steel 
are a fair average : 



Tliickness 


of 


Feet per 


metal 




hour 


20 gage 


40 


18 




35 


16 




30 


14 




24 


12 




22 


10 




20 


. 8 




18 



The welding of steel barrels of about 30 to 35 gal. capacity, 
used for oil or gasoline, can be done by an operator of average 
skill at the rate of 16 to 18 per day. These barrels are made 
of 12-, 14-, or 18-gage sheet steel, and require one seam weld, 
two complete end welds, two bungs welded in and a reinforcing 
ring welded on each end. 

In welding the ends on cylinders or drums, the device shown 
in Fig. 187 is sometimes used. The work rests on a turn table 
which is rotated by the welder's foot. A supporting arm and 
a suspension spring assist the welder in holding the gas torch. 

The method of welding gas containers for war use with 
Oxweld apparatus is shown in Fig. 188. As shown at the right, 
the container bottoms are welded in while resting on rollers 
set on an inclined base in such a way as to present the work 
at the right angle. 

Fig. 189 gives a better view of the bung welding apparatus, 
and also shows the excellent method of suspending the torches 
when not in use. 

LIBERTY MOTOR WORK 

In describing work on the Liberty Motor in the Aynerican 
Machmist, May 29, 1919, H. A. Carhart, mechanical engineer 
of the Lincoln Motor Co., Detroit, first outlines some of the 
electrical welding and then says: "The water jacket is fitted 
to the cylinder, and the latter when assembled, is placed in a 
clamping fixture. Fig. 190. This fixture consists of a frame 



232 



GAS TORCH AND THERMIT WELDING 




WELDING JIGS AND FIXTURES 



233 



with two jaws which are placed around the jacket for holding 
while being tacked. The equipment used in this operation is a 
miniature-style Torch weld torch, equipped with a No. 3 tip 
and using ^/.^An. Norway welding wire. 

"After being tacked, the cylinder is placed in another fixture, 
and the bottom of the jackets are welded to the jacket flange 
on the cylinder. The fixture employed in this operation is a 
fork made of steel 1| in. wide, so shaped as to fit the top of 
the cylinder and thus keeping it in an inverted position. Weld- 
ing the bottom first was considered to be an advantage as the 




Fig. 190. — Tacking Jacket for Liberty Cylinder, 

heat applied at that point had a tendency to draw the jackets 
closer together. It was also considered advisable to leave an 
opening between the jacket halves about V^c in- to Vg, in. to 
take care of the contraction which the different jacket-welding 
operations tended to produce. 

''The cylinder was next placed in a horizontal position on a 
cast-iron table, and the jacket-side seams were welded. The welds 
were started from the bottom proceeding upward to the port- 
holes. The cylinder was then placed in an upright position 
and the top seam completed. The equipment used in this 



234 



GAS TORCH AND THERMIT WELDING 



operation was a miniature Torchweld torch equipped with a No. 2 
tip and ^/^^.-m. Norway welding wire. 

"The next operation was to wekl the jacket around the two 
spark plugs, valve guide and camshaft housing bosses. The 
fixture employed in this operation carries a pilot upon which the 
cylinder can be turned circularly. The equipment used is the 
sam6 as before except that a No. 3 tip was found best. 




Ftg. ]91.— Welding the Inlet Pipe. 

"Next came the welding of the jacket around the porthole 
flange. The fixture used in this operation consists of a standard 
with a revolving cradle to lay the cylinder in. The revolving 
motion of the cradle, together with the varying height of the 
standards, gives, the operator easy access to weld. The equip- 
ment used is a No. 1 Torchweld torch equipped with a No. 3 
tip and Vi^-in. Norway welding wire. 



WELDING JIGS AND FIXTURES 



235 



"The next operation consists of welding both water pipes 
to the jacket and the jacket seams between the valve guide and 
porthole flange. This is shown in Figs. 191 and 192, both 
inlet and outlet being handled in the same fixture. This fixture 
is equipped with two devices for holding the water pipes in 
their proper position while being welded and is so arranged 
that it can be oscillated to suit the position in which the operator 




Fig. 192.— Welding the Outlet Pipe. 

is welding. The cylinder is located by a flat clamp which 
locates the flat on the cylinder bolt flange in proper relation 
to the pipe-holding devices. 

"The jacket seams are welded first, followed by the water 
outlet pipe. In these two cases, the cylinder is welded in an 
upright position. The locating clamp on the bolt flange flat 
is then released and the cylinder given a half-turn to the op- 



236 



GAS TORCH AND THERMIT WELDING 



posite flat. The inlet pipe is then placed in its holding device 
and welded with the fixture in a semi-horizontal position to 
suit the welder. 

' ' The cylinder is then removed and the water pipes inspected 
for proper location. If it is passed, the cylinder is hammered 
with a rawhide hammer to remove scale and loosen any poor 
weld, after which it is tested for leaks. If leaks are found, they 
are repaired hy expert welders and returned for re-inspection." 



WELDING FIXTURES FOR MAKING MANIFOLDS 

Writing in the American Machinist for Mai'ch 25, 1920, C. C. 
Phelps says: "Several ingenious fixtures are employed w great 




Fig. 193. — Fixtures Used in Welding Liberty Motor Manifolds. 

advantage in manufacturing manifolds for the Liberty engines 
by means of the oxy-acetylene process at the plant of the Ireland 
& Matthews Manufacturing Co., Detroit, Midi. The fixtures 
were designed in accordance with plans furnished by the en- 
gineering department of the Oxweld Acetylene Co., Newark, 
N. J. 

"In assembling the manifold parts in the fixture. Fig. 193, the 
five branch inlets are first mounted on their respective pivots A 
in the bed of the fixture ; tlie trunk of the manifold is then 



WELDING JIGS AND FIXTURES 



237 



placed above and in contact with the branch lines, so that 
the openings in the trunk coincide with the ends of the branches, 
and, finally, the five hinged clips B are swung into position and 
clamped down on the assembled manifold by means of the hand 
clamps. The end of the trunk is bent to serve as one of the 
inlets and this end in turn is inserted over the end pivots. The 
fixture shown in Fig. 194 serves to hold the assembled parts in 
perfect alignment. 

"The fixture proper is suspended at the ends to permit com- 



% 



ra 



m 



bMDXSxmXCM 



Fig. 194. — Details of Fixture Proper. Assembled Manifold Indicated by 

Dotted Lines. 




Fig. 195. — Details of Swing Support for Manifold Welding Fixture. 



plete freedom of rotation, and the points of suspension arc so 
-located that the device will be in balance when containing the 
tubing. The support for the fixture. Fig. 195 is mounted on 
a pedestal in such manner as to allow rotation in a horizontal 
plane. Thus the operator is enabled to shift the work so that 
the torch flame can be applied in the most advantageous manner 
at all times. Fig. 196 shows the complete manifold. 

"During the war this company manufactured various kinds 
of tubes and manifolds for Liberty and Le Rhone engines, 



238 



GAS TORCH AND THERMIT WELDING 



bombs, gas shells, floats for the Navy and poison-gas tanks. 
When it is considered that the company had no welding equip- 




FlG. 196. — Coniplutcd Mauifokls for Liberty Eugiues. 



mcnt prior to May, 1918, great credit must be given to the inex- 
perienced girl operators and the equipment that produced such 
results. ' ' 



CHAPrER XIV 
WELDING MACHINES 

Gas-torch welding machines with automatic feed are used 
for a large variety of work, although straight-seam welding is 
the more common. In this latter class of work are included 
sheet-metal-cylinder side-seam welding and pipe or tube welding. 

A welding machine, known as the Duograph, is shown in 
Fig. 197. This machine was made by the Davis-Bournonville 
Co. and was especially designed for welding the seams of steel 
drums or containers, insuring a mechanical weld uniform in 
appearance and efficiency. It comprises a turret-top holding 
device with water-cooled arms and clamps for holding the steel 
drums in position, permitting the work being placed in position 
for welding on one set of arms while the work on the opposite 
set of arms is being welded. The turret top is then swung half 
around, the welded work removed and another job set up. 

The gas-torch carriage is moved forward at a fixed speed 
by power, belt driven, and is reversed by means of a hand- 
wheel when the weld is finished. Various speeds for different 
thicknesses of metal are obtained by the use of cone pulleys. 
The carriage is fitted with two torches — one above, the other 
below — as shown in Fig. 198, for welding both sides of the seam 
simultaneously. For very light welding, one torch only is re- 
quired. Water-cooled welding torches are used. The No. 1 
machine will weld a 36-in. seam, and will take containers from 
12-in. to 36-in. in diameter. The No. 2 machine welds a 54-in. 
seam. An average speed of welding of 18-in. per minute is 
obtained on 16-gage sheets. 

Fig. 199 is a close-up of a man putting a sheet-metal drum 
into position on one of the turret arms. Fig. 200 shows the 
drum clamped down and swung into place ready to be welded. 
This illustration gives a good idea of the operating mechanism. 

239 



240 



GAS TORCH AND THERMIT WELDING 




WELDING MACHINES 



241 




Fig. 198. — Torch Arrangement on the Duograph. 




FiQ. 199. — Putting a Drum Onto a Turret Arm. 



242 GAS TORCH AND THERMIT WELDING 




Fig. 200. — Drum in Position Eeady for Welding. 




Fig. 201.— The Finished Seam Weld. 



WELDING MACHINES 



243 



Fig. 201 shows the seam weki completed and ready to })e 
removed. 

A much simpler machine is shown in Fig. 202. The opera- 
tion of the feeding mechanism is obvious. 

A smaller, though very similar machine, is shown in Fig. 




Fig. 202. — Heavy Drum Welding Machine. 




Fig. 203. — Lioht Seam Welding Machine. 



203. While the work shown in position is cone shaped, cylinders 
may be held as well. 

The machine shown in Fig. 204 is for welding bottoms onto 
tea kettles, cans, drums or other circular work. The machine 
is so made as to allow for a considerable range of adjustment 
for different sizes of work. 



244 



GAS TORCH AND THERMIT WELDING 



The last three machines mentioned were designed by Linus 
Wolf, of the Thermalene Co., Chicago Pleights, 111. 

A machine developed at the plant of the Edison Storage 
Battery Co., Orange, N. J., for welding bottoms in storage- 
battery cases, is shown in Fig. 205. This machine was first de- 
sci'ibed in the American Machinist, Aug. 10, 1911. The bottom 




Fig. 204. — Machine for Weldino- Circular Seams. 



to lie welded in is made of sheet steel with njiturned edges. A 
four-part expanding form is placed within the edges of the 
bottom and locked by turning down the screw shown in the 
center of the case. With the bottom and expanding form in 
place as shown, the ease is "shrunk" to it and sized by turning 
the eccentric lever A. The gas torch B, which is hinged at C, 
is then swung down into welding position and so set as to 
throw the flame correctly onto the upturned edges of the bottom 



WELDING MACHINES 



245 



and the case. The motor is then started and the feed thrown 
in by means of lever D. 

This lever operates a clutch on a shaft carrying a pinion 
meshing with the oblong gear on the bottom of the frame which 




Fig. 205. — Machine for Welding Oblong Seams. 



supports the case. This moves the frame and the seam to be 
welded along under the welding flame. When a corner is 
reached the trip E throws the lever F and slips the clutch G 
into contact with the upper teeth, increasing the speed of the driv- 



246 



GAS TORCH AND THERMIT WELDING 



iiig pinion so that the seam being welded moves at the same speed 
under the flame while turning the corner as while being driven 
along the straight seam. As soon as the corner has been turned 
the lever F is forced down by another trip and the sun-and- 
planet gearing / again comes into play, giving a slower move- 
ment as the straight part of the seam is fed under the flame. 




Fig. 206. — Single-Torch Tube AVeldina; Machine. 



For liringing the mechanism back to the starting point," the 
handle J is used. 

A single-jet tube welding machine made by the Thermalene 
Co., is shown in Fig. 206. Views of a double torch machine 
made by the same concern, are shown in Figs. 207 and 208. 
In a general way, these are typical of all machines designed to 
butt-weld formed tubes. 



WELDING MACHINES 



247 



TUBE WELDING BY THE OXY-ACETYLENE PROCESS 

Writing in the American MacMnist, Nov. 13, 1919, F. M. 
Smith, Chief Engineer of the Oxweld Acetylene Co., Newark, 
N. J., says: "Tubing, considered merely as a structural shape, 




Fig. 207.— Duplex Tube Welding Machine. 

has the greatest strength in compression and bending to be ob- 
tained from any shape of equal cross-sectional area. Likewise, 
it is one of the most convenient shapes known. In large work 
this fact has been applied for years in the use of round cast- 
iron columns and standard commercial wrought-iron pipe of vari- 
ous weiglits, but until the advent of welded tubing nothing but 



248 



GAS TORCH AND THERMIT WELDING 



drawn seamless tubing was available for weights lighter than 
pipe and its price has been prohibitive for ordinary purposes. 
"When the oxy-acetylene welding process offered a means of 
producing the substitute for drawn seamless tubing in the form 
of welded tubing of thin gage, numerous manufacturers were 
so well impressed with the possibilities of this line of work 




Fig. 208. — Another View of Duplex Machine. 

that they went into it on a large scale. As a result, the 
product of the oxy-acetylene tube-welding process is of such 
excellent quality and is produced so much cheaper than drawn 
seamless tubing that it is rapidly superseding the latter form 
of tubing for very many purposes. 

"Tubes welded l\y the oxy-acetylene process are almost in- 



WELDING MACHINES 249 

variably butt-welded; that is, in the tubes as formed up, the 
square edges lie butt to butt. The heat is applied to the seam 
only and must be of an intensity to raise the edges immediately 
under the flame to the fusing point. The edges are then pressed 
together while in a molten condition and flow into each other, 
forming a true and homogeneous weld. The weld may be upset 
or reinforced, if so desired, to a greater thickness than the 
original tubing wall by compression of the seam at the point 
of weld. 

"As the uses of tubing are principally structural, the material 
from which it is made is usually low-carbon steel, although this 
is not used as universally as might be expected because old 
high-carbon rails make an excellent and comparatively cheap 
raw material for the manufacture of tubing by the hot formed 
process, where a smooth and polished surface is not required. 

"The low-carbon steel tubing may be made from either hot- 
or cold-rolled stock. By far, the largest amount is made from 
cold-rolled sheet on account of its smooth finish and good ap- 
pearance. Other metals can be machine-welded satisfactorily, 
but where they are ductile as in the case of brass and copper, 
it may be cheaper to make them by seamless drawing. 

* ' Low-carbon steel us usually purchased from the mills in the 
shape of strips or sheets which can be rolled and sheared ac- 
curately to the required dimensions. Gang shears reduce the 
sheet to strips of accurate width in one operation. The tubing 
is formed cold by first rolling it to semi-circular form and closing 
it in to the circular form either in a conical drawing die or 
by further reductions in size between rolls, the latter being 
generally the preferred process because it eliminates subsequent 
warping at the seam. 

"Rails from which high-carbon tubing is usually worked up 
are broken into the correct lengths to produce a 50-ft. skelp, 
heated in an ordinary heating furnace and broken down to 
rectangular section of the desired gage and width by a series 
of rolls of the usual rolling-mill type. The skelp is then passed, 
while still hot, through a pair of rolls which form the section 
to a half circle and force it through a conical die which draws 
in the edges to the final complete circular section required for 
tubing. 

"Owing to the inaccuracies of this type of mill, the gage and 



250 



GAS TORCH AND THERMIT WELDING 



width of the skelp, which latter dimension determines the 
diameter of the tubing, cannot be held to any close accuracy, 
and, consequently, this type of tubing is used only for purposes 
where exact size is not important, such as bedstead frames, 
handles for tools, and the like. 

"Machines for tube welding consist, in general, of a table 
with frame, or housings, upon which is mounted the feeding 




Fig. 209. — Feeding End of Tube-Welding Machine With Oxweld 
Multiple-Jet Gas Torch. 

mechanism and its drive ; above this, a gas-torch holder equipped 
with a horizontal adjustment at right angles to the seam, 
another in the direction of the axis of the torch and a hinged 
arrangement by which the torch may be lifted away from the 
work. 

"There are two general types of feeding mechanism, one of 
which, covered by the Lloyd patents, consists of a continuous 
or endless-chain arrangement. Two chains are required, one 



WELDING MACHINES 



251 



on each side of the tube, each link carrying a block with a 
groove in its face to fit the tube. Two corresponding blocks, 
when moved forward between rolls upon which the endless 
chains are mounted, catch the tube between jaws and carry it 




Fig. 210.— The Left Set of Eolls Feed the Tubing while the 
Spreader Disk Opens the Seam Slightly. 

The central rolls hold the tubing to specified diameter while welding and the 
right set of rolls act solely as guides. 

forward at a uniform rate of speed, at the same time com- 
pressing the seam the desired amount to secure a satisfactory 
weld. 

"How Rolls Are Arranged. — The other, and more generally 
used method, shown in Figs. 209, 210 and 211, employs two 
trains of rolls, three on each side, having grooved surfaces to 



252 



GAS TORCH AND THERMIT WELDING 



fit the tubing. The middle pair, known as the welding rolls, 
are chamfered away on the top side to allow the welding flame 
to work in between them. The forward and rear pairs are 
used merely as feed and guide rolls. In order that different 
sizes may be welded on the same machine, rolls having grooves 
of varying depth are provided to fit the various diameters of 
tubing to be welded. Provision is also made for opening and 
closing the rolls to get heavier or lighter welds. 

"Experience has shown that to secure an even and smooth 
seam, it is necessary to counteract the effect 'of expansion and 



RE/iR ROLLS 



WELD/NO ROLLS 



FORW/\RD ROLLS 




Elevoiti on Sec+ion A- A 

Fig. 211. — Diagram of Arrangement for Tube Welding. 

contraction by spreading the seam open Vg. in., more or less, 
about 6 in. ahead of the welding rolls. This is generally accom- 
plished by mounting a thin disk abreast of the forward guide 
rolls at such a distance that its lower edge will enter and spread 
the seam apart the necessary amount to secure this smoothness 
of weld. This disk also answers the purpose of aligning the 
seam under the flame. 

"The drive should be arranged to give different speeds in 
order that the machine may be used on different types of weld- 
ing, but should be of such pattern that when once the speed 
is set, it will remain closely uniform. 



WELDING MACHINES 



253 



''There are two general types of oxy-acetylene torches in use, 
corresponding to the two schools of oxy-acetylene practice ; 
namely, the low-pressure and pressure types. The low-pressure 
type is very successful in welding operations owing to the 
'softness' of the flame due to the low velocity of the heating 
gases. It also implies efficiency, as the gases passing over the 
metal at a low velocity have more time to give up their heat. 
The uniformity of the low-pressure flame is because the acety- 
lene is supplied from a gas bell at an even pressure. 




Fig. 212.— Four-Jet Type W-5 Water-Cooled Welding Torch. 




Fig. 213.— Oxweld Type W-8 Single- Jet Water-Cooled Welding Torch. 



"In the welding of heavier gages, more heat is required than 
for lighter work and this is secured by arranging a variable 
number of flames in a line progressively along the seam to 
be welded (see Fig. 212). The forward flames successively 
raise the temperature of the tube to such a point that the last 
flame will fuse the metal just abreast of the welding rolls which 
compress the fused edges together, forming a perfect weld. For 
welding tubing of 14 gage, as high as nine or ten flames have 
been successfully employed and with this number of flames a 
welding speed of 5 ft. per minute can be obtained. With such 
a concentration of heat, water-cooling is necessary to maintain 



254 



GAS TORCH AND THERMIT WELDING 



a uniform flame and oliminato backfiring or ignition of the 
gases within the tip. The torch proper is always water-cooled 
to secure uniformity of flame and for the comfort of the 
operator. For the heavier work, mentioned above, the possibilities 
range down to 22- or even 24-gage metal, upon which a single 
flame torch, Fig. 213, may be employed. Short samples of 
welded tubing are shown in Fig. 214. 

"After welding, if it is desired to secure a very exact diameter, 
either externally or internally, this is accomplished by drawing. 
The operation is performed on the draw bench which consists 
of a long frame, usually horizontal, at one end of which is a 







Fig. 214. — Samples of Tubing Welded by the Oxy- Acetylene 
Machine Welding Process. 

A — Cartridge case. D — Tubing as welded. C and D — All traces of welding eliminated 
by grinding and polishing. E and F — Wind-shield frame and wedge. 

die of chilled cast iron or hardened steel. This die must be 
of the correct diameter and smoothly polished to produce the 
correct finish. It may be cither externally or internally applied. 
When used on the inside of the tubing, it is known as a 
'triblet.' The tubing is entered into the die or over the 
triblet ; the end is crushed to secure a grip for the drawing 
mechanism, which is located at the opposite end of the bench, 
and the tube is then drawn through the die producing the correct 
size and a very smooth finish. Suitable lubricants must be 
applied to the surfaces of the tubes during this process. 

"Where only a bright finish, without exact diameter, is re- 
quired, drawing is not employed — ordinary flashing or polish- 
ing methods being sufficient. If the tubing is to be painted, or 



WELDING MACHINES 255 

for some other reason high polish is not necessary, it is often 
satisfactory, if a smooth weld is secured, to use the tubing just 
as it comes from the welding machine. 

' ' The principal difficulties encountered in tube welding are to 
secure a uniform, continuous and neutral flame and to feed the 
tubing under the torch at a correct and uniform rate of speed 
at the most effective distance from the tip with the seam exactly 
in the flame. 

"The first difficulty is largely solved by using the proper 
torch. The second difficulty is mechanical and can only be 
eliminated by standardizing shop conditions. 

"The stock strip must be held to exact width if a uniform 
diameter and thickness of weld are to be produced. The 
tolerances are determined by experience, but once set should 
be strictly held to. Burrs on the sheared edges must absolutely 
be eliminated as these get into the seam and hold it open causing 
'skips.' When the strip is formed into tubing, care must be 
taken to secure a very exact adjustment of the rolls and dies 
or otherwise the seam in the tube will assume a spiral shape, 
causing difificulties in guiding the seam exactly under the flame. 
If the flame does not play exactly upon the seam, only one 
side of the seam will be fused and the weld will 'skip' until 
the flame is correctly adjusted. Lost motion in the feed rolls 
and in the adjusting mechanisms of the torch holder will invari- 
ably aggravate this difficulty. 

"In the early days of this art, when manufacturers were 
content with speeds of 2 to 3 ft. per minute, it was possible for 
the operator to adjust his flame from side to side, follow the 
irregularities in the seam, and to slow down his machine when 
the Aveld showed a tendency to skip. With the speeds attained 
in modern production, from two to four times as fast as 
formerly, this is no longer possible. The operation progresses 
so rapidly that it is humanly impossible for the operator to 
adjust his machine to changing conditions and, in consequence, 
if the seam is not perfectly true the operator must necessarily 
fail to get a continuous weld and even in attempting to do so 
he will constantly slow down his machine, thus limiting the 
quantities of tubing produced. 

"The successful manufacturers have, therefore, applied the 
well-known principles of scientific management to this problem 



256 GAS TORCH AND THERMIT WELDING 

and by studying the conditions under which the forming and 
welding are done have succeeded in so standardizing their 
product that the welder is not required to do anything but start 
the tube into the machine and keep the torch lit and the tip 
free from accumulations of slag and dirt. The tubing is re- 
quired to come absolutely uniform in diameter and straight in 
seam. The set of the rollers, speed of welding and pressures 
of the gases in the torch are adjusted by the foreman or tool 
setter in charge to predetermined standards which are not 
allowed to be changed by the operator. If, with the machine 
as delivered to the operator, he cannot secure good tubing, the 
machine is shut down, the trouble discovered and the proper 
remedy applied. 

"By the application of such methods as these and with the 
full cooperation of the manufacturer of oxy-acetylene apparatus, 
it is not remarkable that great progress in the development of 
the art of oxy-acetylene tube welding should have been made 
within so short a time." 



CHAPTER XV 
CUTTING WITH THE GAS TORCH 

The gas-torch cutting process consists of heating a spot of 
the metal to be cut to a good red heat and projecting on it a 
jet of oxygen. This causes the metal to burn away, a stream 
01 slag running out of the kerf thus produced. Cutting is not 
melting, in the ordinary sense, although since the heating flame 
is the only visible agent, such might be the beginner's conclu- 
sion. It should be remembered that the heating flame is only 
used to make the metal hot enough to oxidize easily. 

Metals whose oxides have a lower melting point than the 
metal itself can be cut by the gas torch. Such metals are 
wrought iron and steel. Where the oxide has a higher melting 
point than the metal, cutting with the gas torch is either im- 
possible or not satisfactory. Such metals are copper, brass, 
aluminum, cast iron, etc. 

A big factor in successful cutting is to properly support the 
body and torch to as great an extent as possible commensurate 
with the steady forward movement of the torch. The position 
must be an easy one, as muscles under tension will cause vibra- 
tions and these are fatal to good cutting. An ideal position for 
an operator, is shown in Fig. 215, although in actual, every-day 
practice one usually has to be satisfied with less desirable con- 
ditions. 

Theoretically, with the cut once started the oxygen jet alone 
should be sufficient to keep up the combustion, as there is con- 
siderable heat generated in the process. However, the stream 
of oxygen is small and the burning metal confined to a very 
narrow slot, and scale, dirt, sand, blowholes and other things 
interfere to prevent the continuation of the cut of the jet with- 
out an accompanying heating flame. 

A cutting torch is lighted in the same way as for welding, 
except allowance must be made for the drop in the oxygen 

257 



258 



GAS TORCH AND THERMIT WELDING 




Fig. 215. — Au Eii^y Cuttiiii; Positiori. 




Fig. 216. — Starting a Ciit With a Davis-Bournonvine Torch. 



CUTTING WITH THE GAS TORCH 



259 



pressure when the cutting jet is turned on. This allowance 
can be made by regulating the flame while the jet valve is 
open, which is done before starting to work. 

When the flame is adjusted, hold the torch as shown in Fig. 
216, the left hand grasping it well toward the head and the 
right hand on the handle with the thumb- or fingers controlling 
the jet level valve. The metal to be cut may be a piece of 




Fig. 217.— Making a Clean Cut Thronah a Plate. 



heavy boiler plate, steel bar or structural steel. Rest the elbow, 
forearm or hand on the plate to steady the torch. It is usually 
best when cutting without a guide wheel, to arrange to cut 
either to the right or to the left rather than toward or away 
from the operator. However, an operator should learn to cut 
in any direction. "When it is possible, always start on the 
edge. Hold the flame on one spot until it is a nice red, then 
turn on the high-pressure oxygen jet. Hold the torch steady 



260 



GAS TORCH AND THERMIT WELDING 



with the luminous cone almost touching the metal, until the cut 
goes through. Sparks should show as in Fig. 217. If they 
fly, as in Fig. 218, the cut is not going through. 

In the cutting of plates, it is advisable to tip the torch head 
in the direction of the movement, once the cut has progressed 
a little. This rule does not apply in the case of blowing holes 
in metal where the nozzle must be tipped away from the slag 




Fig. 218. — Cut Not Going Through Properly. 



SO that no particles will impinge on the orifices or a back pressure 
be created on these orifices. 

If the metal is very thick, the oxygen pressure will have 
to be high. In beginning a cut of this type, it is necessary to 
blow the oxide out at the bottom before the cut has traversed 
very far into the body of the metal, otherwise, a pocket will be 
formed and it will be impossible to penetrate to the bottom of 
the metal. In cutting heavy material, success depends entirely 
upon the ability of the individual. The nozzle must be turned 
outward in preheating and must be carried inward with the 



CUTTING WITH THE GAS TORCH 



261 



tip gradually moving to a vertical position and finally forward 
as the cnt progresses. In blowing holes, as in Fig. 219, the 
metal must be blown away from the tip, and to accojnplish this 




Fig. 219. — Blowing a Hole Through a Plate. 




Fig. 220.— Cutting OflE a Eivet Head. 



it is advisable to begin with a very Avide kerf, produced by 
rapid movement of the torch sideways while carried away from 
the origin of the cut. In this way the oxygen penetrates deeper 
into the metal while the torch is moving, until, finally, the 



262 



GAS TORCH AND THERMIT WELDING 



oxygen emerges at the bottom, when the torch can be brought 
to a final cutting position and the metal cut in any direction. 

Rivet head cutting in shipyards is generally accomplished 
by means of a specially designed nozzle, which rests upon the 
plate so that the preheating jets and cutting jet will act at the 
base of the rivet head as shown in Fig. 220. In blowing out 
countersunk rivet heads, the same procedure must be followed 
as in blowing holes, but more precautions are necessary in 
order that particles of metal do not impinge on the preheating 
orifices and clog them or cause backfire. 

The "nicking of billets" became very common during the 




ti^iG. 221. — [Isinsr I^ollcrs and a Bar Guiilo. 



war. A narrow, shallow cnt is made on one side or around 
the circumference of a steel section, then the billet is snapped 
oft' ;it the nick in a press or hammer. 

When a cut must he ''easonably smooth, use wheel guides, if 
possi])le. If a straight line must be followed, a bar of metal 
may l)e clamped to the work as shown in Fig. 221. A good 
way to both guide the cut and support the operator's hand, 
when cutting ship plates is shown in Fig. 222. This principle 
may be applied to other wtu'k 

For cutting circles, a radius attaclimeiil is used, similar to the 
one shown in Fig. 22:) Tiiis device is made by the (*arho- 
liydrogen Co., Pittsburgh, Pa., but practically every torch manu- 
facturer makes something of the kind. 



CUTTING WITH THE GAS TORCH 



263 



The way llic cul on a 12-i]i. shaft kwks is shown in Fig. 224. 
This was cut with an Oxweld low-pressure torch. Tlie chalked 




Fig, 222. — Cutting Ship Plates. 













'i 


4 




c 


? 


i 




J 


;| 


'■ 





Fig. 223. — Kadiiis Cutting Attachment for Straight-Tip Torch. 



arrows indicate a blowhole and a crack which materially re- 
tarded the cutting. This cut took 3 min. 27 sec. and about 
75 cu.ft. of oxygen was used. A similar cut, under similar 



264 



GAS TORCH AND THERMIT WELDING 



conditions, bnt made without encountering any flaws in the steel, 
was made in )> iiiin. 10 sec. and 67 en. ft. of oxygen was used. 

On woi'k 1 in. thick or over, a slot of from Vi,; to ^ in. is 
about right. For thinner stock, or when using a machine, the 
slot may often be reduced to less than Vj,., in. by a skilled operator 
with special tips. 

Flame Control. — In woi-ldng liold the flame so that the end 
of the cone just clears the metal — do not attempt to plunge it 




Fig. 224.— a 12-Tii. Shaft Cut with a Gas Toix-h. 



down into the cut. When cutting two plates or more, or where 
there is a lap joint, remember that there is more or less of an 
insulation (air, dirt, etc.) between these plates and that the 
oxidation cannot be as fast as where only one thickness is cut. 
Remember that the flame does not do the cutting — therefore, 
work with the smallest flame possible — it means a neater cut. 
Keep the oxygen pressure as low as possible and yet maintain 
speed. A high pressure is spectacular and there are a great 
number of sparks, but it is not economical and a wider kerf 
is made. Do not use the torch with greasy gloves — a spark 



CUTTING WITH THE GAS TORCH 



265 



in combination with a leak on the oxygen supply will badly 
l)urn the hand. If a cut must be started in any place except 
on the edge, drill a hole or use a cold chisel and a hammer 
to roughen up the surface, the idea being to get an edge to 
quickly stai't oxidation. 

Making- a Ladle Hook. — As an instance of the many savings 
lliat may l)e obtained by the intelligent use of the gas-torch 
cutting process, the following will be of interest : 

At one of the shipyards scrap ship plates are cut into special 
shapes for building up large hooks like the one shown in Fig. 
225. These hooks are used for handling large ladles in a 
near-by steel mill and have resulted in a great saving. 



H 


■ 


HH 




■ 




s^' 










HHi 


■ 


m 


^ 




1 






i^ 


g 


I » '*jj _^. 




H 


Q^^^ 




^^v^^ 












1 






^^^^i^^i 



Fig. 225.— Ladle Hook Made of Toreh-Cut Plates. 



The hooks are 8 ft. in total length and are made up of six 
layers of plates which run the full length, with four short 
layers, all securely held together with countersunk rivets. The 
four inner plates are each ^ in. in thickness. The two outer 
full-length plates are of ^-in. material. Adjoining the latter 
plates on either side is a half-length plate ^ in. in thickness. 
The hook proper is still further reinforced by two slightly shorter 
outer plates, each | in. in thickness. 

The plates are first marked with the aid of a templet to 
serve as a guide for the cutting torch. After cutting, they are 
assembled and riveted as shown in the illustration. A laminated 
construction of this sort is not only exceptionally strong, but 



266 



GAS TORCH AND THERMIT WPJLDING 



is a decided economy, as it makes use of what would otherwise 
be waste material. 

Firemen are frequently confronted with locked steel doors 
or barred windows. These readily yield to a properly applied 
cutting torch. Fig. 226 shows a fireman demonstrating how 
an Oxweld emergency cutting outfit may be used. The entire 
kit weighs 118 lb. 

A very wide field for the cutting torch is in reducing scrap 
to workable dimensions. The figures here given regarding the 
cutting of scrap, are taken from a bulletin issued by the Oxweld 




Fig. 226. — Fireman Demonstrating an Emergeney Kit. 



Co. Where costs are cpioled the estimates should bL' about 
doubled for present conditions (1920). 

An operator recently cut two twenty-ton steel fire boxes into 
sci'ap, prepared for the shears in twelve hours. More than 300 
lin.-ft. of cut was made th]-ough |-in. plate (considering the 
mud ring and over-lapping plates). The total cost for oxygen, 
acetylene and labor was $24.10 per fire box — cost per ton $1.22. 

In another case a locomotive boiler was cut into scrap at 
ii total cost of $2.68, the numl)er of lineal inches cut totaled 
210 through ^-in. plate, 9 through 3-in. plate and 172 through 
f-in. plate. This amount of cutting was completed in fifty- 
three minutes at a cost of 8 cents per foot for tlie various 
thicknesses. The foreman in charge of this job stated that the 
work done by one operator in one and one-half days would 



CUTTING WITH THE GAS TORCH 267 

require the services of two men for, at least, a week, with 
ordinary working methods. 

A ten-ton boiler was reduced to scrap read}' for shears by 
one operator in nine hours at a total cost of $16.00 or $1.60 
per ton. 

On another piece of work, the operator cut 78 ft. of 4-in. 
plate in two and one-half hours. One piece of this plate, 18 ft. 
long, was cut in 13 min. The cost of cutting the 78 ft. was 
$4.25 or $0,054 per foot through the. ^-in. plate at a rate of 
over 30 ft. per hour. 

A three-ton boiler averaged $2 per ton cut in one and one- 
half hours. The total length of cut equaled 60 ft. 4 in. It 
would have cost $3 to $4 per ton to cut this boiler by hand. 

A fourteen-ton boiler was cut at the rate of $1.23 per ton 
in nine hours and at a total cost of $17.38. One hundred and 
eleven feet eight inches of cut was made at the rate of $0,149 
per foot. 

Three fire-box boilers weighing ten, twelve and fourteen tons 
respectively were scrapped at the average rate of $1.40 per 
ton. The users of this plant state that the apparatus enables 
them to cut into scrap five locomotives Avhere one was handled 
by the methods used before the Oxweld process M^as employed. 

Cutting steel car frames into scrap shows equally important 
savings in time and money. 

A five-ton car frame was cut in two and one-half hours at 
an average cost of $2 per ton. It was cut into 4^-ft. lengths 
through three and four thicknesses of plate in some parts of 
the frame. 

A record kept of cutting about 12,000 lb. of wrecked steel 
car frames shows a total cost of $8.10, or about $1.35 per ton. 
These frames were cut into 4|- to 9-ft. lengths, in five hours. 

CUTTING CAST IRON WITH THE GAS TORCH 

In a paper read before the American Welding Society, 
April 22, 1920, Stuart Plumley and F. J. Napolitan, of the 
Davis-Bournonville Co., outlined some of their experiments in 
relation to the cutting of cast iron with a gas torch. 

They said in part : 

While we are rather skeptical of the coiiimercial value of a cast- 
irou cuttiiiix torch, and are convinced that, financially, we shall never 



268 GAS TORCH AND THERMIT WELDING 

be repaid for the expense of our experiments, yet there are un- 
doubtedly occasions when tlie cutting of cast iron wouhl be of great 
value. In oi'dinary scrap-yard work, it is so easy to lireak cast iron 
that it would hardly be economic to use the cutting torch as for steel. 

You are all aware, of course, of that application of oxygen cutting 
used largely in blast furnace practice, the opening of a "frozen" tap 
hole. You could not (luite reconcile this more or less conmion applica- 
tion of the process with the pet theory that cast iron could not be 
cut. One of the usual methods for releasing a frozen tap hole in a 
blast furnace is substantially as follows : A piece of |-in. iron pipe 
with a brass handle at least 10 ft. long is attached to a manifold of 
several oxygen cylinders. Oxygen is delivered through this pipe at 
a pressure of approximately 100 lb. per sq. in. A hole is started with 
a star drill or diamond point, until it is about 3 in. deep. The metal 
adjacent the hole is heated with a fuel oil burner or by other means. 
The end of the iron pipe is ignited and the composite stream of 
molten iron slag and oxygen caused to impinge against the frozen 
cast iron. 

A spectator to this performance of infernal fury, is readily con- 
vinced that the heat is not all due to the combustion of the wrought 
iron pipe, but that the cast iron is Ijurning with a violence equal to 
that of steel. This reaction inspired some inventors to incorporate 
a device in an oxy-acetylene torch for cutting cast iron, which would 
feed a steel wire between the cutting jet and the cast-iron piece being 
cut. Ignition of the wire carried a stream of molten slag on to the 
cast iron and it was hoped thus to propagate the cut. In a second 
process, a plate of steel of a definite and predetermined thickness, was 
placed on top of the cast iron. It was hoped that the slag incidental 
to the oxidation of the steel would exercise some influence over the 
cast iron and enable it to be cut. 

Unfortunately for those responsible for the exploitation of these 
devices, the inventors were more concerned with converting cast iron 
into iron oxide by means of the oxy-acetylene torch than they were 
in constructing a practical process and a practical tool. It was next 
proposed to simplify the reaction by supplying an apparatus with a 
mixture of pulverized slag and iron powder, and in fact a number of 
patents were issued covering various applications of such a device. 
Crude and elementary as such devices were, they actually produced 
combustion of the cast iron and went a long way in stimulating us 
in our endeavors to find a successful method. 

Experimental work was carried on with a torch having a good 
many different tubes leading to the head so that almost any com- 
bination of gases at varied pressures might be obtained. Mr. Napolitan 
evolved from these experiments interesting theories i)ertaining to the 
reactions which take place in cutting, together with their relation to 
success in cutting cast iron. He has noted these theories in a separate 
paper. We are presenting these thories to the members of the society 



CUTTING WITH THE GAS TORCH 269 

for wliiil tlu'.v arc wortli. We ciiii jictually cut cn.st iron and we do 
it l).v ]»•< h< (liiiui fli( oxiKjcn. 

Ill the i)apei' prepared by Mr. Napolitan, he said: 

From tlie ease with whicli \\rouglit iron is cut we may conclude 
that an aggregate of ferrite comhines with oxygen witli greatest r.vidity, 
and permits the propagation of a cut with least interruption. As the 
carbon content is increased, there is a material change in the nature 
of the metal. In place of the preponderance of ferrite grains, we 
recognize the formation of cementite, and its union with some of the 
ferrite to form pearlite — tlie original mass of pro-eutectoid ferrite 
rapidly diminishing in prominence. As we should anticipate from the 
nature of pearlite, no material change is noticed in the performance 
of these alloys under the cutting torch. Of course, an ultra-pi-ecise 
consumption test would probably indicate a lowering of the efficiency 
coefficient, but from all appearances no unusual difficulty is experi- 
enced in cutting carbon steels up to about 80 to 90 point carbon. But 
here, a definite transition is indicated by a distinct laboring of the 
cutting torch. While the torch will begin to cut with practically the 
same effort, and proceeds to completion without interruption of un- 
usual delay, yet the kerf is wide and ragged and undeniably dis- 
tinguishable from that of a mild steel cut. It is recognized practice, 
now, to preheat the piece to be cut to a black or dull red heat, when 
the impediment, whatever it was, seems to have been entirely 
eliminated. 

But let metallography explain the sudden change of properties of 
the steel. As the carbon content of the hyper-eutectic steel was in- 
creased, the proximate mass of pearlite increased, and the pro-eutectoid 
ferrite correspondingly diminished in volume, until eventually a point 
was reached where all of the cementite and ferrite existed in the 
stratified or laminated relationship of pearlite. This state is recog- 
nized as existing where the carbon content is between 80 and 90 points 
— the approximate analysis of pearlite is yet undefined. As the carbon 
content is further increased, there appears a constituent that we know 
as pro-eutectoid cementite — in fancy, the cementite which has been 
ejected from the pearlite growth. It is circumstantial that the presence 
of this pro-eutectoid cementite is directly responsible for the increasing 
difficulty of our cutting. But why did preheating of the steel before 
cutting make such a remarkable difference in the results? To be sure, 
the rise in temperature might affect the stability of any martensite, 
troostite, or even sorbite that might have existed, but the temperature 
was too far removed from the ACa^i point to affect the characteristics 
of the pearlite. And surely the pro-eutectoid cementite was unchanged 
— and it was this same constituent that we blamed for the difficulty. 

Again, as the carbon content is substantially increased, an equivalent 
interference with cutting is api)arent. until, when the carbon content 
approaches 2.5 per cent, cutting becomes so labored as practically to 
cease, and no amount of preheating short of incipient fusion will 



270 GAS TORCH AND THERMIT WELDING 

permit it to propagate. As you are aware, the metal is now termed 
"cast iron," and a micro-analysis indicates that in addition to the 
presence of a certain amount of pearlite and pro-eutectoid cementite, 
as well as certain foreign and, to our discussion, unol)trusive sub- 
stances, we i-ecognize the presence of the final and most stable state of 
carbon-graphite. The pearlite constituent exercises a favorable in- 
lluence upon the operation of cutting — ^and the pro-eutectoid cementite, 
while it impedes cutting, is readily compensated by a slight preheating 
— but the graphite presents an entirely new problem. 

We might digress from the subject enough to present some remarks 
that would prove the fallacy of at least one of the stereotyped ex- 
planations of why cast iron cannot be cut — that the melting point of the 
slag is appreciably higher than the melting point of cast iron. 

A micro-analysis of the structure of an average cast iron — and by 
average we refer to a gray cast iron of about three to four per cent 
carbon — would indicate a structure identical with ih:it of a hypothetical 
steel of the same carl)on content, except that some of the 
carbon seems to have been precipitated as graphite. But should 
that identical pour of cast iron have been cast against a cold iron 
mold, or otherwise chilled, the carbon would not have been pi'ecipitated 
as graphite and we should have had what we shall call a "chilled 
cast iron," or a "white cast iron," — and it would actually have been 
a hyper-eutectic steel. Sucli alloys are not uncommon in com- 
merce, and the fact tliat operators have lieen able to cut 
them with no extraordinary effort has lieen responsil)le for in- 
numerable false claims that cast iron has been cut. Unfortunately, 
the nomenclature of steels and irons is not clearly defined, and un- 
doubtedly a chilled cast iron is but an extension of the hyper-eutectic 
series. The melting point of an iron-carbon alloy is a constant of 
its composition, whether, in the solid state, the metal exists as a typical 
cast iron or as a steel. Long before the point of fusion, the carbon 
and the iron exist in one relationship, that of austenite. The condi- 
tions affecting the pouring of a melt of cast iron would determine the 
final state of its constituents — and we nught.as readily produce a 
gray cast iron or a chilled white cast iron — the carbon as graphite 
or the carbon as in cementite. In either event, the melting points of 
the resulting products would be identical. We agree that chilled cast 
iron can be cut with comparative ease. It is evident, then, that the 
melting point of slag is not resi)onsil)le for the difficulty encountei'ed 
in cutting cast iron. 

We had concluded that while the existence of pro-eutectoid cementite 
appreciably retarded cutting, the presence of but a comparatively 
small amount of graphite completely prevented cutting. The phenome- 
non, if it were true, is unique, for it would pre-suppose the incom- 
bustibility of carl)on. Science contradicts us innnediately. In fact, our 
own welding practice belies us. We might point to the reaction 
accompanying the removal of carbon from automotive cylinders by 
the oxygen method — or, leaving our immediate field, we might mention 



CUTTING WITH THE GAS TORCH 271 

the explosive combustion of carbon in ordinary gun-powder. We are 
forced to conclude then that, far from retarding the combustion of 
the steel matrix, the graphite of cast iron should actually assist it. 

We investigated further to determine how much graphite influenced 
cutting. AVe obtained specimens of so-called malleable castings of the 
characteristic "black heart" structure. Such a structure is made in 
this country by the annealing of white cast iron in which all of the 
carbon exists in cvmentite or pearlite, the latter in some cases entirely 
removed. The treatment decomposes the cementite to precipitate the 
carbon in minute particles, differing from the graphite of gray cast 
iron in their extreme subdivision and uniform distribution throughout 
a ferrite matrix. In making a black heart casting, an oxidizing pack- 
ing is used in this country so that while the core is that of a black 
heart casting, the mass near the surface is ferrite. We removed this 
shell of ferrite so that our materials indicated, under the microscope, 
a uniform aggregate of ferrite and temper carbon. By preheating this 
piece to a dull red heat, it was cut with the characteristics of a high- 
carbon steel. Then we were satisfied that carbon as such did not 
prevent cutting, but that the physical state of that carbon was responsi- 
ble. As plates of graphite, cutting was prevented ; but as finely 
divided particles, cutting was scarcely impeded. 

Reconsidering our previous observations in the light of this de- 
velopment, we began to substantiate our first logical hypothesis. We 
found, to summarize, that ferrite permitted most readily to be cut. 
Pearlite with pro-eutectoid ferrite did not materially affect the condi- 
tions. A completely eutectic "composition first suggested a transitory 
stage. The existence of pro-eutectoid cementite retarding cutting ; but 
preheating of the piece to a red heat readjusted the conditions so that 
cutting was again as efficient as in the case of ferrite. As the com- 
paratively low temperature produced by preheating was insufficient to 
effect any change in the physical state of the constituents of the 
alloy, w-e were forced to conclude that the addition of heat units 
affected a definite constant, which we assumed was the heat of com- 
bustion of the iron, as the two forces were of like characteristics. 
Then a constant result from a variable made axiomatic the existence 
of a second variable. Our second variable then, we concluded, was 
the cooling effect of the stream of cutting oxygen, and a further 
thought suggested a third variable in the time of chemical reaction 
between the iron and oxygen. The preheating flames ignited the 
steel — the cutting oxygen produced combustion — and the pi-opagation 
of the cut was a natural consequence. But as the carbon content was 
increased, the speed of the reaction was materially lowered; however, 
the velocity of cutting oxygen to insui'e a continuity of oxygen and 
slag to the bottom of the cut, was a constant. Then, eventually, a 
point was reached where the rate of combustion between the iron and 
oxygen was so slow that the heat units liberated from the reaction 
were dissipated to such an extent as no longer to ignite adjacent 
masses of metal— and cutting ceased. By preheating the piece before 



272 



GAS TORCH AND THERMIT WELDING 



cutting, we add to the forces on the weakening sido of the equilibrium, 
and cutting once more obtained. The heat units so obtained com- 
pensated for the relatively less heat units liberated from the chemical 
combination of the iron and oxygen in a definite unit of time. 

While the pearlite and pro-eutectoid cementite are readily com- 
pensated, the graphite carbon effectively prevents cutting by the ordinary 
means. No addition of heat units short of incipient fusion, by pre- 
heating the object, restores the equilibrium. We cannot strengthen 
further one side of our equilibrium, but we have not attempted to affect 
the other side. We had made no attempt to reduce the cooling effect 
of the cutting oxygen. We therefore experimented in this direction, 
and found that we could so effectively preheat the cutting oxygen that 
we could restore the equilibrium without preheating the object. 

In regard to the foregoing it will be of interest to the 
reader to know that the following article was published in the 
July, 1919, issue of Autogenous Weldi7ig: 




Fig. 227. — Four Corners of Large Oast-Iron Stone Crusher Head Beveled 
with Cutting Torch for Welding. 



"Substantial progress has been made which shows that cast 
iron cutting with the torch is a practical commercial proposi- 
tion. Proof is shown in the two views of the four corners ol 
a large stone crusher head that were prepared for welding by 
beveling the edges with the torch as shown in Fig. 227. The 
job was accepted in our welding shop, with a promise of com- 
pletion in two days, but it was found that a much longer time 
would be required alone to bevel the edges by chipping. The 
Staff of the Engineering and Research Department of the Davis- 



CUTTING WITH THE GAS TORCH 273 

Bournonville Co., which had been experimenting in cast iron, 
was appeaknl to, with the result tliat the four pieces were made 
ready for welding in less than one hour ! 

"Each corner piece represents a cut 4-2- in. thick and 17 in. 
long, with an area of 76 sq.in. The cuts were made in 6^ 
min. each, using 24 cu.ft. of oxygen and about 4 cu.ft. of 
acetylene. The cut surface produced was smooth and the edges 
were sharply defined, as is shown in the views. The kerf was 
about Vju-in. wide at the top and bottom — about the same as 
would be produced by cutting steel of the same thickness. The 




Fig. 228 — Cutting Torch Made to Preheat the Oxygen Cutting Jet. 

process was not one of melting, as the sharp edges prove — in 
fact the finish of the cut surfaces compares favorably with that 
of steel. After the cuts were started they were carried through 
to completion without a stop, and the pieces dropped apart of 
their own weight." 

Since it is known that the cutting of cast iron is principally 
accomplished by preheating the oxygen, attention is called to 
the fact that there have been cutting torches on the foreign 
market for several years so made as to preheat the oxygen cut- 
ting jet. One of these is shown in Fig. 228, the principle on 
which it is made being self-evident. 

Another torch which is a combination carbon electrode and 



274 



GAS TORCH AND THERMIT WELDING 



oxygen jot is shown in Fig. 229. This was patented by R. E. 
Chapman and J. W. Kirk in 1918. The construction is obvious 
as the electric current source and connections are shown at the 
left and .the oxygen tank and tuliing at the right. The carbon 
electrode has a hole in the center through which the oxygen jet 
is projected. As the temperature of the arc is considerably 




Fio. 229. — Carbon Electrode and Oxygen Jet Torch. 

higher than that of the gas torch the oxygen is highly heated 
as well as the metal. 



OXY-HYDROGEN CUTTING 

Elmer II. Smith, secretary of the Commercial Gas Co., writing 
in the Welding Engineer says : 

As I had never had the opportunity to get an accurate cost on 
oxy-hydrogen cutting, either through experience of others or through 
my own worlv I was very glad to tal^e the data on a recent jol) wliere 
I could get absolute facts and figures. 

The work consisted in splitting a number of steel plates l.S/lG-in. 
thick by -(> ft. 10 in. long and was done by one of our spring motor 
cutting torch carriers with our standard straight line torches with a 
No. 1 cutting tip made especially for hydrogen cutting. 

As cutting is a process of burning we convert the iron to iron oxide 
or FesOj, which means that the burned iron is composed of three 
parts of iron and four parts of oxygen. Since the atomic weight of 
one part of iron is oG as comitan'd to IG for oxygen, this means that 
the weight of the oxide would l»e composed of ;> X -"'^J i^^^it weights of 
iron and -IxlO unit weights of oxygen, or a ratio by weight of 16S 
parts of iron to G4 parts of oxygen. In other words, if we were to 
take 232 lbs. of slag produced by cutting it would contain 64 lbs. or 
about 700 cu.ft. of oxygen and IGS lbs. of iron. 

For means of comparison the following figures are set forth, showing 



CUTTING WITH THE GAS TORCH 275 

what tlio jj^as coiirsuiiiptiou wovild be on this particular class of work 
if the cutting was done with theoretical efficiency. 

Fe304 = Fe IGS, O 64 (pts. by weight). 

2G ft. 10 in. = 322 in. 

322 in. — 13/lG-in. thick = 261.6 sq.in. of cut. 

4 cuts = 1046.4 sq.in. 

1046.4 sq.in. of cut 3/32 in. thick ^98.1 cu.in. metal removed. 

Steel weighs .2831 lb. per cu.in. 

98.1 cu.in. weighs 27.8 lbs. 

Now if all the oxygen used had combined with the iron to do the 
cutting Ave would require 64/168 of 27.88 lbs. or approx. 10.6 lbs. of 
oxygen. As 1 lb. oxygen equals 11.209 cu. ft., the amount required 
theoretically is 118.81 cu.ft. In actual practice, however, we cannot 
obtain any such efficiency, as the cutting jet must be of sufficient 
volume and pressure to blow out the slag and clean the kerf of oxide. 
This means that an excess of oxygen must be used to do the more 
or less mechanical part of the work. In addition some oxygen must 
be supplied to coml)ine with the hydrogen to provide the heating jet. 
None of this oxygen is used in converting the iron to FejOi and 
represents a total loss as far as the theoretical figures go. 

Of course if we expected to get down to exact figures we should 
have an analysis of the steel to be cut and allow for the oxygen neces- 
sary to convert the carbon and manganese to oxides, but the proportion 
is so small as to be almost negligible. 

Now let us see what obtains in actual practice in machine cutting 
of ordinary steel ship plates free from rust but coated with the usual 
amount of thin mill scale. 

I set up the motor and after a short trial adjusted the oxygen 
pressure to 22 lbs. pressure and the hydrogen to 3 lbs. This oxygen 
pressure may appear a trifle high, but it must be remembered that it 
was not only efficiency in gas that was desired but also saving in time 
and there was too the friction of a 25-ft. length of hose to overcome. 
(I have often cut 1-in. steel with less than 10 lbs. pressure.) I then 
adjusted the speed of the machine to 14 in. per minute which was 
the maximum speed at which the cut w-ould clear itself perfectly. The 
pressure gages, previously tested for accuracy, showed 1780 lbs. on the 
oxygen and 1800 lbs. on the hydrogen drum. At the end of the run 
the gages showed 305 lbs. on the oxygen and 1175 lbs. on the hydrogen. 
As the drums were 200 cu.ft. capacity the consumption was 1475/9 = 
164 cu.ft. oxygen and 525/9 z= 70 cu.ft. of hydrogen. As the oxygen 
for the heating jet was supplied from the same drum and through the 
same regulator as the oxygen for the cutting jet it was impossible to 
determine the amount used in the heating jet, but I would estimate 
that it was approximately 30 cu.ft. as it was much more than is used 
in any oxy-hydrogen welding flame. This would leave 134 ft. oxygen 
for the actual cutting operation, which is but 15.19 cu.ft. more than 
the theoretical amount required. The kerf was just a few^ thousandths 
of an inch under 3/32 in. which would throw the balance against the 



276 GAS TORCH AND THERMIT WELDING 

cflicieiu-.v slightly, but eoniputiiig from the aliove ligures it is shown 
that the actual results are SS per cent of the theoretieul tigures. On 
account of the laclc of definite figures on cost of cutting with either 
the oxy-acetylene or oxy-hydrogen process on actual cutting jobs it 
might not be amiss to compute the foregoing figures to show the 
approximate cost per sq.in. of cut. 

I'urity of oxygen 99.5. 

I'urity of hydrogen 99.8. 

1288 lineal inches 13/16 in. thick ==: 1046.4 sq.in. 

164 cu.ft. oxygen @ l^c $2.46 

70 cu.ft. hydrogen @ Ic 70 

Total gas cost 3.1 7 

Total oxygen cost per sq.in. cut .$.00235 

Total hydrogen cost per s(i.in. cut 0007 

Total gas cost per sq.in. cut .$.00305 

Oxygen per lineal ft.... 1..53 cu.ft. 
Hydrogen per lineal ft. . .65 cu.ft. 
Total gas cost per lineal ft. cut $.02945 

These figures cannot be obtained in free-hand cutting and could 
not be expected as the cutting jet must be maintained at a considerably 
higher pressure to overcome the unsteadiness on the part of the operator. 
The heating flame must also be larger in free-hand cutting, or the cut 
will frequently be lost requiring the operator to turn off the cutting 
jet and start ovei". 

From the figures given me on the use of oxy-acetylene cutting in 
which the oxygen was approximately 98 per cent pure, the cost of the 
cut per lineal ft. was Oc. However, I did not conduct the test with 
oxy-acetylene and am taking the results obtained by the foreman in 
charge. He stated that the pressure in the oxygen was 35 lbs. and on 
the acetylene 8 lbs. The resulting cut was not nearly so smooth nor 
regular as that produced by the oxy-hydrogen and in addition there 
was an accumulation of slag at the bottom of the cut which was 
entirely absent when hydrogen was used. 

We all know that if oxygen is diluted with a very small quantity of 
incombustible gas, such as carbon dioxide, its efficiency is greatly 
reduced and a decrease of 4 per cent in purity results in an increased 
consumption of 60 per cent in oxygen. But we may start out with a 
very pure oxygen in oxy-acetylene cutting and still have a high consump- 
tion, which would lead one to believe Hiat the oxygen of the cutting 
jet is diluted after it leaves the cutting tip with the products of com- 
bustion of the heating flame, which contains carbon monoxide, which 
is not present in the oxy-hydrogen flame. 

It was interesting to note that when the heating jet was adjusted 
to heat at about the same rate as oxy-acetylene in starting the cut 
the top of the kerf was very slightly melted over making a rounded 



CUTTING WITH THE GAS TORCH 277 

edge, but that when the Ihiiiie wiis so adjusted that it required a half 
u iniiiute or more to start the cut tlie top edges of tlie kerf were 
sliarp and square as they were at the bottom. Altliough with the 
flame adjusted at a point requiring 30 seconds to start the cut, after 
it was once started no trouble was experienced by losing the cut and 
in every case the full 26 ft. 10 in. was cut without an interruption, 
except on the extreme end of one piece which had a thick scale of rust. 

Although it is seen that in this particular case the consumption of 
hydrogen is considerably less than half the amount of oxygen, my 
experience has not been quite so satisfactory in cutting scrap iron, 
that is scrap boilers, etc., where there is more or less rust and boiler 
scale to contend with and also the frequent interruption of the cutting 
operation in shifting from one piece to the next. In cases of this 
kind the heating flame must be of ample capacity to penetrate the 
scale and to start tlie cut almost immediately. It is also the custom 
to have the torch burn while moving about from one cut to the next. 
This increases the hydrogen consumption about 100 per cent more or 
less depending on the operator. The thickness of the metal to be cut 
also determines the proportion of hydrogen used. It is probably safe 
to say that the amount of both gases used will be practically doubled. 

If it would not complicate construction to the point of imprac- 
ticability it would be a step in the right direction to make a cutting 
torch with a valve control that would open first the valve controlling 
the combustible gas, then the oxygen for heating jet and lastly the 
cutting jet valve. 



CHAPTER XVI 
CUTTING MACHINES 

Wliere close cutting to a line or pattern with a gas torch 
is desired, some mechanical device must be provided for guiding 
the torch. A properly constructed machine saves time, mate- 
rial and gas. 

The more common mechanical devices in use are for feeding 




Pie. 230. — Cutting a Billet with au Oxweld Machine. 

the torch in a straight line. These are used to cut bars, bil- 
lets, boiler plate, armor plate and the like. An Oxweld 
straight-line cutting machine is shown in Fig. 230. An ordinary 
cutting torch is used in this case, and the end of a 12 X 12-in. 
billet has just been cut off. The feed screw may be turned from 

278 



CUTTING MACHINES 



279 



citlicr end by means of handwlieels, and means are provided 
for cross adjustment. 

Another device, made by the Davis-Bournonville Co., is shown 
in Fig. 231. The pieces, which were cut the long way, measured 
15 X 13^ in. This machine has a liandwheel on one end of the 
feed screw and a cone pulley, for power drive, on the other. 
Unlike the device first shown this one is not mounted on legs 
but has a short section of I-beam for a base. On this account 




Fig. 231. — Another Straight-Line Cutting Machine. 



it may be placed on the object to be cut or laid on blocks or 
horses, as occasion demands. 

The device shown in Fig. 232 differs from either of the 
foregoing in that racks are used in place of lead screws. This 
is made by the Great Western Cutting and Welding Co., San 
Francisco, Cal. The heavy structural iron base is so made that 
it may be placed on the work, laid on blocks or horses or mounted 
on legs. Means are provided for adjusting the torch up or 
down or at an angle. 

Any of these machines may be used for cutting out marked 
square, rectangular, round or irregular shaped holes. Where 



280 



GAS TORCH AND THERMIT WELDING 



the metal is thick, it is often better, especially on repetition work, 
to drill a liolc tlirou^h for starting-. 

The Kadiagraph.— Tlic Radiagraph shown in Fig. 283 is 
made by the Davis-Bournonville Co. It is a motor-driven device, 
with oxy-acetylene or oxy-hydrogen cutting torch, adapted to 
cutting along straight lines or circles in steel plate from -^ in. 
to 18 or 20 in. in thickness, the speeds varying from 2 in. to 18 
in. per minute, according to the thickness of the plate. For 




Fig. 232. — Portable Cutting Machine with Rack Feeds 

straight line cutting, it operates upon a parallel track, and for 
circle cutting, with a rod and adjustable center. The device 
consists principally of a three-wheeled carriage driven by an 
electric motor attached to the carriage, which may be connected 
to the ordinary lighting or power circuit, either d.c. or a.c, 
110- or 220-volt circuit. An adjustable arm and torch holder 
provides for raising or lowering the torch while in operation, 
and for adjustment at an angle for bevel cutting. The adjust- 
able arm also permits of following an irregular line within a 



CUTTING MACHINES 



281 




Fig. 2'A'A. — Davis-Rournoiiville Radiagrapk 




Fig. 234.— Radiagraph Cutting Steel Plate at the New York 
Shipbuilding Yards. 



282 



GAS TORCH AND THERMIT WELDING 



variation of 3 in. on either side of a straight line. The cutting 
torch is connected by hose to the gas supply. The machine is 
portable, weighing approximately 50 lb. complete, and has proven 
an invaluable aid in steel cutting, greatly facilitating such work 
in shipyards and steel mills, several machines being employed 
advantageously in some of the larger plants. 

An example of some of the straight line cutting done by the 
Radiagraph is shown in P'ig. 234. Here the track has been 




Fig. 235. — Davia-Bournonville Raiiograph. 

laid on a heavy piece of ship plate and the torch is fed along 
at a uniform rate by the motor. 

The Raiiograph. — For cutting railway rails the device shown 
in Fig. 235 is used. This is clamped to the rail while it is in 
position on the roadbead if desired. The cutting torch may be 
mounted in a holder on either side of the rail. Each holder 
is carried by a slide. Attached to each holder is a roller which 
runs in contact with a cam formed in such a way that it pro- 
vides for maintaining the tip of the cutting torch at a uniform 
distance of about J in. from the surface of the work as the torch 
is fed around the rail. Feeding of the torches is accomplished 
by two handwheels which transmit motion through a set of 



CUTTING MACHINES 



283 



siiital)le gearing. In operation the torch is first applied at one 
side of the rail and fed over the line on which the cut is to be 
made, one-half of the base and head of the rail and the web 
l)eing cnt in this way. The torch is next removed from the 
holder and mounted at the opposite side of the rail, where it is 
again passed over the line of cut, with the result that the remain- 
ing half of the base and head of the rail is severed. A 9-in. 
traction rail can be cut off in about three minutes. 




Fig. 236. — Cutting Heavy Plate at the Schneider Works, Creusot, France. 



The cutting of heavy steel plate in the great Schneider 
Works, Creusot, France, is shown in Fig. 236. The portable 
devices are very similar to those used in the United States. 
In the background is a huge machine so made that it can be 
used to trim ends, square up a plate and cut angles or circles. 
The torch carriage is fed along by a lead screw run by a motor 
seen at the extreme right. A motor-operated device will raise 



284 



GAS TORCH AND THERMIT WELDING 



or lower the frame or give it a circular movement. The plates 
to be cut are run into position on small flat cars. 

Circular Cutting-.— The l-tacliagraph cutting- circles, is shown 
in Fig. 237. The work was 2^ in. thick and was cut at the rate 
of 6 in. per minute. Note the true circle and surface of the 
cut. The pieces were for a special type of heater for the Gov- 
ernment. The round piece, or flue sheet, is 30 in. in diameter 
and the ring, or flange, 45 in. outside diameter. 

Another device is tlie Holograph, shown in Fig. 238. It 




Fig. 237.— Radio,i;raph Used for Circular Work. 

is a device for cutting holes in the web of a rail, or in struc- 
tural iron, of not more than ^ in. thick. It is quickly attached 
and accurately adjusted. It pierces through the iron almost 
instantly, without any previous drilling, and will cut smooth 
round holes from 1 to 2 in. in diameter in from 30 to 60 sec.' 
It is particularly adapted for railroad work, and enlarging or 
cutting holes in building and bridge work. 

The Mag-netogTaph. — The Magnetograph shown in Fig. 239 
was designed for mechanically cutting circles up to 12 in. 
diameter in steel plate in perpendicular position, such as cut- 



CUTTINC; MACHINES 



285 



tiii<>' poft liolcs in tlic side ])lal(>s ot: sliips. Stool plalo fi-om 
-] ill. up to several inches tliick is cut quickly, witli a finished 




Fig. 238. — Davis-Boumonville Holograph. 




Fig. 239. — Davis-Boiirnonville Magnetograph. 

and true surface, the movement of tlie oxy-aeetylene or oxy- 
hydrogen torch and flame being given by handwheel and gears. 



286 



GAH TORCUI AND THERMIT WELDING 



(Alt ting is accomplished at varying speeds according to thick- 
ness of plate, from 3 in, up to 20 in. per minute, oi' even faster 
on light plate. The device is constructed as much as practical 
of aluminum to obtain lightness, and is held firmly on tlie plate 
by means of three electromagnets, connected by wire to an 
electric circuit (direct current) or to battery. 

The Camograph.— The Camograph, Fig. 240, is an adapta- 
tion of the Holograph. It is of the same general construction, 
except that it is larger and has a wider range of work. It 
is fitted with a cam for each particular kind of work, and 




Tig. 240. — The Camograi^h. 



will cut almost any form desired, within the capacity of the 
machine. This machine requires special cams iov each 
operation. 

The Camograph No. 2, shown in Fig. 241, is a later develop- 
ment of the Davis-Bournonville Co. It is automatic in opera- 
tion and is used for cutting openings in steel plates that cannot 
be done conveniently or economically on a drilling machine. 
The torch is mechanically traversed over a fixed path and at 
a predetermined speed. The path followed is controlled by 
an internal cam at the top of the machine, the shape of which 
determines the shape of the opening being made, the double- 
jointed radial arm permitting universal movement of the flame 



CUTTING MACHINES 



287 



which perforates the steel. The principle of the cam guiding 
action is unique. The feed roller is magnetized by a powerful 
electromagnet, and is thus attracted to the inner face of the 
cam, the parts in contact being made poles of the magnet, one 
of which rotates and thus acts as a traction driver. The roller 
is driven by a sniall variable-speed motor through double worm 




Fig. 241. — Camograph No. 2. 

gearing, the magnetic attraction being sufflcient to cause it 
to travel along the face of the cam in a positive manner. 
Direct current is required owing to the magnetic feature, and 
the control consists of a double push-button switch for starting, 
stopping and also for energizing the magnet. Arrangement is 
provided whereby when the cutting oxygen is turned on the 
feed motion automatically starts. The nominal diameter of 



288 



GAS TORCH AND THERMIT WELDING 



the largest hole cut is 7 in., but openings other than circular, 
liaving one dimension much larger, may l)e provided for. All 
thicknesses of plate used on the largest marine boilers are 
readily cut with this machine. The macliine is 17 in. wide, 
15 in. deep, 25 in. high, weighs 125 lb., and uses 110 volt, 
direct current. 

The Great Western Cutter. — The machine shown in Fig. 
242 is made by the Great Western Cutting and Welding Co. 




FiQ. ^4:2. — (.ireut Western Cutter. 



It is designed to cut round, square or oval holes. Three 
master plates are furnished for holes of these shapes. By- 
turning the handle the torch travels around the inside of the 
form, to which it is held by the two coiled springs shown. The 
machine is simple and liglit. Extensions are furnished for 
cutting large holes. For odd-shaped holes extra plates are 
required. This machine is especially adapted for boiler shops, 
shipyards, etc., in cutting hand holes, manholes, fire-box door 
holes, and holes in tube sheets. 



CUTTINCx MACHINES] 



289 



Tlir maoliine shown in Fig. 243 is known as the Pyrograph 
and is made by the J)avis-lU)urnonvillc Co. The model sliown 
is not the latest, but well illustrates the general principles of 
the more impi-ovcd ones. It was designed primarily for boiler- 
shop use in turning flanged boiler heads or cutting openings 
for doors, manholes and the lilvc. In one shipyard boiler plant, 
flanged combustion chamber heads, f in. thick with a flange 
periphery of 27 ft., were trimmed and beveled to the calking 
angle in 30 min., exclusive of the setting up. 




Fig. 24;>. — Pyrograph Trimming and Beveling Boiler Flanges. 

As can be seen, the Pyrograph comprises a motor-driven 
carriage supported on a radial arm of* a length that provides 
for cutting the flange of a 9-ft. diameter boiler head at one 
setting. "While the largest diameter circle that can be cut 
at one setting is 9 ft., much larger work may be trimmed and 
beveled, inasmuch as the arm can be swung through a semi- 
circle of 20 ft. or a full circle of 20 ft. diameter, provided 
the shop conditions permit the arm to swing in a complete 
circle. Heads larger than 9 ft. diameter are reset as many 
times as may be found necessary to reach the flange all around. 

The radial arm construction is light but rigid, consisting 



290 



GAS TORCH AND THERMIT WELDING 



of two cokl-rollcd parallel round steel bars firmly tied together 
by end connections and intermediate spacer blocks, and sup- 
ported by a truss rod. The vertical cast-iron pivot member 
of the radial arm is mounted on ball bearings at the top and 
bottom, in order to insure the maximum ease of movement. 
The steel post around which the radial arm swings is adjustable 
vertically by means of a crank operating a rack-and-pinion 
gear. A dog and racket hold the post at any height within 
the limits of adjustment required. 

The colum-U has a broad flanged base which may be bolted 




Fig. 244. — Details of Pyrograph Feed Mechanism. 

to a cast-iron floor plate or a concrete foundation if required 
to be self-supporting, or the top of the post may be shackled 
to a column of the shop building and the base supported on 
an ordinary floor without an individual foundation. 

The carriage is supported on the radial arm by four grooved 
ball bearing rollers which provide for the easy radial move- 
ment required to follow the feed action freely. The carriage 
and the arm derive their movements from the feeding 
mechanism which operates directly on the part to be beveled, 
the flange part itself acting as the track and guide for the 
feeding mechanism, as shown in Fig. 244. 



CUTTING MACHINES 291 

The torch is adjustably mounted on the carriage beneath 
the radial arm, and the tip may be directed at any angle 
required to cut to the desired calking angle. 

The flange to be trimmed and beveled is gripped between 
the three feeding rollers, two of which are small idlers on the 
side next to the torch while the driving roller, considerably 
larger, is located on the far side of the flange. The driving 
feed roller derives its motion from a small electric motor 
mounted on top of the carriage and driving through a reducing 
train of worm and bevel gears. Variations of speed are pro- 
vided by making the upper worm and worm gear replaceable 
with worm gears of different ratios. The following speeds are 
available: 12 in. in 70 sec, 12 in. in 90 sec. and 11 in. in 
60 sec. 

The pressure on the feed rollers required to produce the 
traction necessary to traverse the torch and carriage is obtained 
from the weight of the torch, the slide rests on which it is 
carried and the frame to which the two idler feed rollers are 
attached. The frame carrying the slide rests and idler feed 
rollers is pivoted, and the weight forces the idler feed rollers 
against the side opposite the driving roller with sufficient 
pressure to traverse the carriage positively. The feed mechan- 
ism operates on any shape whether straight or curved, thick 
or thin. Flanged sheets are generally rough, presenting a more 
or less irregular contour, but this does not interfere with the 
carriage traverse and the torch action. The operator may 
interrupt the feed at any point by raising the frame, thus 
relieving the pressure on the feed roller. 

The driving roller and its shaft are protected by a shield 
of fireproof composition having a beveled flange at the bottom, 
on which the sparks and slag have no effect. The machine, 
once set, trims a flanged sheet evenly all around, provided 
the sheet has been properly leveled. OtherAvise it is necessary 
to chalk a line to be followed. 

In the plant of the New York Shipbuilding Corporation, 
three different combustible gases are used in cutting torches, 
namely, carbo-hydrogen, acetylene, and hydrogen. The com- 
bustible gas selected for different classes of work depends upon 
the thickness of the plates Avhich have to be cut. The range 
of thickness handled by the different gases is as follows: Up 



292 GAS TORCH AND THERMIT WELDING 

to 3 in., earbo-liydrogcn ; 3 in. to 6 in., acetylene; and over 
6 in., hydrogen. It will, of course, be understood that either 
of these gases is mixed with oxygen. 

A Universal Cutter. — A machine built somewhat along the 
lines of the Pyro graph, but a much more universal machine, 
has been developed for use in the shops of the Genei'al Electric 
Co., Schenectady, N. Y. This machine is sliown in Fig. 245. 
It can be set for automatically making circular, spiral, radial 
or tangential cuts. Its rate of feed can be varied from 1 to 
72 in. per minute, according to the character and thickness 
of the metal. The base of the machine is provided with a 




Fig. 245. — Automatic Universal Cutting Machine. 

powerful electro-magnet to be used if the machine is placed 
on a rough or uneven surface and also to hold it in position 
when it is necessary to perform cutting operations on work 
held in a vertical plane. Ordinarily, the weight of the machine 
is sufficient to hold it steady. As shown, the machine is mounted 
on a truck for easy transportation, as it weighs 1,900 lb. 

The Oxygraph. — With the Oxygraph, steel plate from 1 in. 
to 15 in. or more in thickness is cleanly cut with a narrow, 
smooth kerf, along straight lines, sharp angles, or curves, 
according to drawing or pattern. The pantagraph principle 
is employed, with a motor-propelled tracing wheel, with which 
the lines of the drawing are followed and reproduced with 



CUTTING MACHINES 



293 



the cutting torch. Either the oxy-aeetylene or the oxy- 
hydrogcn cutting flame is used, with hose connection to the 
source of gas supply. The only power required is for revolving 




Fig. 246. — yingie-Torch Oxygraph. 




Fig. 247. — Oxygraph with Two Torches. 



the tracing wheel, and this is supplied by a small motor attached 
to the tracing head, which may be connected to the ordinary 
electric light or power circuit. A universal motor, either d.c. 
or a.c, 110- or 220-volt circuit, with rheostat and friction 



294 



GAS TORCH AND THERMIT WELDING 



governor is used. Tlic speed of cutting varies from 2 to 18 in. 
per minute, according to the thickness of steel being cut. 

One size of machine is applicable to small work and die 
cutting, within a cutting area of 16 in. square, a circle of 18 
in., or a rectangular form 12X40 in. may be cut by extension 
of the tracing table. With this machine, a drawing or pattern 
double the size of the cut to be made is required, the drawing 
being placed on the tracing table shown at the right in Fig. 246. 

Another machine is made for larger, heavier work. It has 
a double pantagraph frame and is fitted with two cutting 
torches for making duplicate cuts at the same time, the position 




Fig. 248.— Cuttinq- Out a Large Slot. 



of the torches and tracing wheel being adjustable. The entire 
pantagraph frame may be moved backward from the table 
to allow placing of heavy plate with a shop ei-ane. This 
machine reproduces the cut of equal size with the pattern, 
or 1 to 1. 

A machine with two pieces of work and iDattern in place 
is shown in Fig. 247. 

Another practical application of the Oxygraph is shown 
in Fig. 248. The piece worked on is a fishing tool used for 
fishing out broken tulics in oil wells. This Oxygraph has a 
bed frame 30 in. wide l:)y 9 ft. long. The fishing tool is hollow, 
with walls 2^ in. thick, and weighs 900 lb. The total cut made 
of 21 lin. ft. was made in 21 min. or 1 ft. per minute. 



CHAPTER XVII 

WELDING SHOP LAYOUT, EQUIPMENT AND WORK 

COSTS 

The layout and equipment of a welding shop will, of course, 
vary with the class and amount of work handled, the capital 
available, and the personal opinions of the owner. One should, 
however, have enough equipment of a mechanical nature to 
insure the finishing of work in a reasonable time without too 
great an expense for labor. A first class workman can, when 
necessary, turn out a good job of difficult work with a single 
welding and cutting outfit; means for preheating which may 
consist of a few firebrick, asbestos and charcoal ; a chisel or 
two ; a good hammer and a few files. These are insufficient, 
however, where any amount or variety of work is to be handled 
economically and to the satisfaction of the ordinary run of 
patrons. A minimum amount of mechanical equipment should 
include a number of hand and handled chisels, several ham- 
mers and sledges of different weights, a portable electric 
grinder or at least a grinding stand, and a portable electric 
or a stationary drilling machine, or both. To this, for more 
extensive work should be added a pneumatic or an electric 
chipping hammer, a lathe, cranes, and possibly a portable or 
a stationary motor-cylinder grinding machine. Oil- or gas- 
burning i3reheaters are also almost a necessity in any case, 
while a gas-burning preheater of the table type, will save an 
enormous amount of time and trouble on the general run of 
gasoline motor work. Special grated iron welding tables, heavy 
surface plates and grids, iron blocks and straps and numerous 
other articles will need to be added as local requirements 
dictate. 

The shop layout for equipment will liave to conform to the 
building unless the shop is built purposely for the work. In 
this connection very few suggestions of any value can be made, 

295 



29G 



GAS TORCH AND THERA/IIT WELDING 



except that tlie shop manager should endeavor to so place his 
equipment as to cause the least running back and foi-tli possible. 
We will, for the benefit of our readers give tlie layout of 
a large shop doing nothing but Avelding work. This is the 
shop of the Oxweld Acetylene Co.^ Newark, N. J., and it was 
built expressly for this work. Allowance in position had to 
be made for the set directions of the railroad and street lines. 




Fig. 249.— -Exterior View of Oxweld Shop, Showing Crane Hoists. 



Fig. 249 shows the end of the Iniilding next to the railroad. 
The overhead track for the chain blocks is so placed as to 
be readily used for loading or unloading either cars or trucks. 
This is good, but a still better arrangement would be to extend 
the runway on into the shop itself and so save considerable 
rehandling in order to get the work to or from the welding 
floor. Fig. 250 is a floor plan showing the location of the 
various benches, lockers, machines, etc. 



WELDING SHOP LAYOUT 



297 



/jpunoj 




298 



GAS TORCH AND THERMIT WELDING 




WELDING SHOP LAYOUT 



299 




300 



GAS TORCH AND THERMIT WELDING 




WELDING SHOP LAYOUT 



301 



111 Fiji^. 251 is shown a view of the shop just inside the 
nortlu'i'ii end. Tlu> doors sliown at the rifflit are tlie ones 



Working Order— Welding Shop 


JOB No . DATE _ _ tSI 


NAME - - 








ADDRE!)S 






























PER HOUR. GAS. MATERIAL AND EXPENSES EXTRA. INVOICE S - 








SA 

^ AMT. OF COMMIS 










SION S _ 










91 








SHOP TRANSIT 


GAS 


LABOR I 


*RT,CLE 




TOTAL 


P«,CE 


TOTAL COST 


%"%%". 


IcftYltne 


Dati 


""-nT' 


HCU., 


HATE 


total] 


Chahcoal . 
































PRIHKATINO 
































Cast iaon 
































?/on'w%e 
































*•■"« R°«:::: 
































e.ONZK 
































Bma» 




















■ 












Flux 
































STIKk RSb 




















TOTALS 








1 1 


A«BeiTO« 
















INDIRECT CHAHG 




OlovK* 


















Cahbon. Block 
Gogol C5 

















TOTAL 























OVER HEAD _ «..._ 1 


___.— 









.. 





Gas AMT. Phicb Totau 




O.T..M 






5 




BO.OO O.D 
















EXPMCSS 















ACtT.L.NE 






S. 




_ 1 
















r s.,^ ,„ 


CARTAn 












BASE 














TOTAL COST-SHOP TRANSIT % 


COM. TO SALESMAN - S 1 


"'"*""■ 


PROFIT FOR COMPAN 


v..._ - s....._, J 







































Fig. 254. — Cost Keeping Form. 

that open ont nnder tlie crane shown in Fig. 249. This interior 
view in Fig. 251 gives a good idea of the lighting and the 



.302 (iv\s -roRcri and ^riij-:RMiT welding 

ventilators at the top for eari-ying away the fumes. Tlie air 
and acetylene pipe lines are shown, aiid in tlie left foregj'ouncl 
is illustrated in the way cylinders are chained. In the central 
foi'eground one of the workmen is chipping a casting with a 
pneumatic chisel. 

The opposite end of the shop is shown in Fig. 252. Here 
a portable crane is shown in the middle foreground. Suspended 
from it is a portable electric grinding machine. Just back of 
this is an electi'ic grinding stand. At the right, in the back- 
ground, is a "Wiederwax preheater and just in front of this 
is an iron preheating and welding stand with an operator at 
work at it. 

At the left in Fig. 253 is shown a number of welding tables 
with grated (tast-iron tops and welded angle- and strap-iron 
legs. Both the daylight and artificial lighting are excellent 
throughout the shoj). Probably no other shop would be built 
(exactly like this, as conditions differ so radically, but a careful 
study will reveal to the prospective shop man some of the 
things that will, or will not, apply to his particular case. 

Keeping Track of Costs.— No shop can succeed financially 
without keeping a close watch on cost of material, gas, labor, 
overhead, etc. The way this is done in the Oxweld shop will 
be seen by referring to the form shown in Fig. 254. This is 
so made as to cover both inside and outside jobs. These forms 
are made in duplicate on white and pink paper, so that a 
cai-bon of the original is made. These forms are for shop and 
office use only, and from them the customer's bill is easily 
made out. With forms of this kind, the entire data relating 
to any job may ])e had at any time hy reference to the files. 

Another form of cost card, suggested by the Imperial Brass 
Manufacturing Co., is shown in Fig. 255. This is not so com- 
plicated as the form just given, and will answer in many eases. 
The manager should not forget, however, to add to this the 
cost of overhead, which it is wise to make fairly high to allow 
for contingencies — say from 100 to 150 per cent. 

Carbon Burning-. — While carbon burning has nothing to do 
with welding, the ordinary welding shop is often called upon 
to do such work on account of having a supply of oxygen 
at hand. 

(!ai-bon in a motor cylinder is caused hy imperfect com- 



WELDING SHOP LAYOUT 303 

bustion. It may be that the carburetor was not adjusted so 
as to give sufficient air, or it may be too much oil was uSed. 
The use of oxygen is the most practical and thorough way 
to remove this deposit. 



Oxygen gage, start ISOO lbs.=100 cu. ft. 

Oxygen gage, finish 900 lbs.= 50 cu. ft. 

Oxygen used 900 lbs.= 50 cu. ft. 

Acetylene used : 

50 cubic feet @ .$0,025 ,$1.25 

Oxygen used : 

50 cubic feet @ .02 1.00 

PREHEATING COST 

Charcoal 

Gas, i hour, 2 burners @ .GO .30 

Kerosene 

LABOR (Preparing) : 

1 hour 30 inin. @ .GO .90 

LABOR (Welding) : 

1 hour 30 niin @ .GO .90 

LABOR (Finishing and testing) : 

1 hour niin @ .30 .30 

RODS : 

Lbs. Steel @ 

15 Lbs. Cast Iron @ .10 1.50 

Lbs. Bronze @ 

Lbs. Copper @ 

Lbs. Aluininiuii @ 

FLUX: 

4 Cans Cast Iron.. . , » , . . . . o , . o o = . . . o , , . .(5) .50 .25 



Total $G.40 



REMARKS 



Fi(i. 255. — Suggestion for Cost (Jaid. 



A decar])onizing outifit is shown in Fig. 256. Here A is the 
oxygen tank valve, B the tank coupling, C the pressure gage 
showing the pressure at which the oxygen is delivered to the 



304 



GAS TORCH AND THERMIT WELDING 



"torch," D the regulating screw, E hose connection, F trigger 
valve, 6r hose connection and H the flexible copper tip. 

To use this outfit, connect it up as shown, then with the 
motor running shut off the gasoline and let the motor run 
down. If the engine is particularly dirty, it may be advisable 
to protect the carburetor and pan by placing some asbestos 
paper at points to prevent fires from flying sparks. 





Fig. 256. — Imperial Decarbonizing Outfit. 

Remove spark plugs from cylinders — not the valve caps. 
Crank the motor until the cylinder to be started upon has the 
piston at the top, with both valves closed. 

Set the pressure on the regulator at about fifteen pounds 
and partially depress the lever on the handle of the carbon 
burner. 

Use a Avax taper or drop a lighted match into the spark 
plug opening of cylinder, at the same time directing the copper 



WELDING SHOP LAYOUT 305 

tube of the carbon Inii'iier at that point. This ignites the 
carbon, and it* it is not too dry, the oxygen shonUl thereafter 
be sufficient to completely consume it without again lighting 
it. At the start, particularly if the cylinder is oily, there will 
be some flame as well as considerable sparks. Hold the pressure 
down until the flame has practically disappeared, then press 
down the lever all the way and move the nozzle back and forth 
around the walls until sparks stop. 

Sometimes the cylinder is very dry and the carbon is rather 
difficult to burn. This can be more or less determined by the 
appearance of the spark plug. If it is dry, squirt about a 
teaspoonful of kerosene into the cylinder, spreading it over 
as large a surface as possible, to aid the burning. 

The copper tube is flexible and may be bent as desired 
to reach any portion of the cylinder. Actual contact with 
the carbon by the tube is not necessary to consume it — carbon 
burns in an atmosphere of oxygen after it is ignited. 

The only possible danger to the cylinder, valves or piston 
is a too high pressure of oxygen on an extremely oily cylinder 
— there would be considerable heat generated in this instance. 
Hold the pressure down, then, until the flames have gone and 
sparks only are being thrown out before fully opening the lever 
on the handle. 

When through cleaning, it is desirable to remove the valve 
cap and blow out any solid particles there may be present; 
these solid particles cannot be carbon, but may be pieces of 
iron, etc. The appearance of the cylinder will be considerably 
improved by swabbing off the top of the piston and valves with 
an oily rag. 

Carbon burning is a very practical solution of carbon de- 
posits — but care and horse sense must be used, though the 
process calls for no particular degree of skill. 

SAFETY RULES FOR GAS-TORCH WORKERS 

The following rules were adopted in 1920 by the Western 
Pennsylvania Division of the National Safety Council : 

Equipment Rules 

1. All pressure tanks should be fitted with safety relief devices, 
and tanks not so equipped should not be used. 



o()(3 GAS TORCH AND THERMIT WELDING 

2. The cqnipinenl sliould include a higli-pivssure gage to indicate 
the pressure on tlie taid;, a reducing valve, and a low-pressure gage 
to indicate the pressure on the torch. These should he assenihled as 
one unit and so arranged that they need not he separated when they are 
attached to, or detached fror.i, the tank. The two gages should have 
different-sized openings: one should have a right-hand thread and the 
other a left-hand thread so that they cannot he interchanged. There 
should he one of these units for the oxygen tank and one for the 
acetylene tank. 

3. All pressure regulators should he equipped with a safety relief 
valve which will relieve the pressure from the diaphragm and low- 
pressure gage in case the high-pressure valve should develop a leak. 

4. Wire-wrapped hose should not lie used. 

5. The oxygen and acetylene hose should he of different color or 
the couplings should he stamped for identification purposes, so as to 
avoid interchanging the hose. 

6. The torches should l)e of a type which will not hacktire. 

Rules for Opeeation 

1. Under no condition should acetylene he used where the pressure 
is greater than 15 Ih. per square inch. 

2. Special care should he given to the storage of oxygen and acet- 
ylene tanks. Acetylene is classed as an explosive, and only a limited 
number of containers should be stored in any one place. Oxygen tanks 
should be stored in a separate place from acetylene tanks. 

o. Oxygen and acetylene tanks should not be allowed to remain 
near stoves, furnaces, steam heaters or other sources of heat, and 
should not be exposed unnecessarily to the direct rays of the sun, 
as an increase in the temperature of the gas will cause a corresponding 
increase in the pressure within the tank. Any excess of heat may 
also soften the fusible safety disk with which the tank is provided, 
causing it to blow out and permitting the gas to escape. 

4. Oxygen tanks should never be handled on the same platform 
with oil or grease which might find their way into the valves on 
the tanks. 

5. Oxygen and acetylene tanks should never be dropped nor handled 
roughly, and should never be stood on end unless fastened so as to 
prevent them from falling over. 

6. Tanks should not be handled by crane, either magnetic or 
mechanical. 

7. All empty tanks should be marked plainly with the word "empty" 
and returned promptly to the storeroom. 

8. An open flfime should never lie used for the purpose of discovering 
leaks in acetylene tanks. Tweaks can generally l»e detected ])y the odor 
of the acetylene gas, and their location can be determined by applying 
soapy water to the surface of the tank and watching for the soapy 
bubbles formed by the escaping gas. 

9. No repairs to oxygen or acetylene tanks or equipment should be 



WELDING SHOP LAYOITT 307 

inado or altciniilcd. All dclVcts should 1)0 reported ijroniptly to tlu' 
rorcniiin, and liy liiiii to the niaiiui'acturcr. 

Id. lA'akiii,u' act'tylonc tanks should not be used, but should l)i' 
placed in the oi)en air and all open lights be kept away from then). All 
leakin,u acetylene tanks should be reported promptly to the foreman and 
innnediately returned to the manufacturer. 

11. All open liames should be kept away from any place where 
there is any possiliility of acetylene escaping;. 

12. Care should l)e taken to protect the discharge valves of tanks 
from being bumped, as a jar may damage the valve and cause it to 
leak. 

i:>. Grease in contact with oxygen under pressure may cause spon- 
taneous ignition, (treat care should l)e taken not to handle threads 
or valves with oily hands or gloves, and gages should not be tested 
with oil or any other hazardous carbon. If a lubric;int must be used, 
the purest glycerine is permissible. 

14. Gages, apparatus and torches requiring repairs should be sent 
to the manufacturer, and local repairs should not be attempted. Valve 
seats sliould never be replaced except by the manufacturer. 

15. The use and operation of the pressure regulator or reducing 
valve on oxygen or acetylene tanks should be as follows: (a) Open 
the discharge valve on the tank slightly for a moment and then close 
it. This is to blow out of the valve any dust or dirt that might 
otherwise enter the regulator. (b) By means of the stud or nut 
connection on the regulator, connect the regulator to the discharge 
opening of the tank, (c) Release the pressure-adjusting screw of the 
regulator to its limit, (d) Open the needle valve slightly if there is 
one. (e) Open the discharge valve on the tank gradually to its full 
width, (f) Open the needle valve to its maximum if there is one. 
(g) Adjust the pressure-regulating screw until the desiivd pressure 
is shown on the low-pressure gage. 

16. The discharge valves on the tanks should be opened slowly, 
and care should be taken to avoid straining or damaging them by 
the use of a hammer or the wrong kind of wrench. A special wrench 
should be made for use in opening these valves in case they stick. 

17. When the operation of the cutting or welding torch is stopped 
for a short time, the needle valve on the regulator should be closed, 
or the pressure-adjusting screw should be released to keep the pressure 
off the hose. The torches should be opened momentarily to let the 
pressure out of the hose lines. 

IS. All tanks should be inspected at the close of the day's work. 

19. Proper precautions should be taken to protect the hose from 
flying sparks. 

20. All hose should be examined periodically at least once every 
week. This should be done by cutting the hose off at the end of 
the connection and examining it. In addition, after a few months' 
use, the hose should be cut off about two inches back of the connection 
and examined for defects. A defective hose should never be used. 



308 GAS TORCH AND THERMIT WELDING 

21. Special care sliould l>e taken to avoid tlie intercliange of oxygen 
and acetylene hose or piping, as this might result in a mixture of these 
gases that would he highly explosive. The practice of using right- 
and left-hand threads is recommended. 

22. White lead, grease, or other similar substances should never 
he used for making tight joints. All joints and leaks in equipment 
should be made tight by soldering or In-azing. 

23. The oxygen and acetylene valves at the base of the torch should 
he tested daily for leaks. 

24. Where hydrogen or other gas is used instead of acetylene, the 
same precautions should be observed as for acetylene. 

25. A lire extinguisher should be carried as regular equipment to 
be used in case of fire. 

26. Men vising welding apparatus should wear suitable welding gog- 
gles for eye protection, having frames tliat are nonconductors of heat 
(not celluloid), side shields to protect against hot particles of metal, 
and lenses of proper color. 

27. Operators' clothing should be fireproof. 

28. If valves become frozen, they should be thawed by hot water, 
not by flame or hot metal rod. 

29. Home-made generators should never be used, as they are unsafe. 
Only generators permitted by the Board of Underwriters should be 
used. 

30. Where acetylene is used from generators or is piped through 
the plant, an approved water seal should be interposed between the 
generator and the piping system, and individual water seals should 
be placed at each blow-pipe. Water seals should be inspected daily 
without fail. 

31. Portable generators should not be used inside the building. 

32. Safety devices on tanks, generators, or apparatus should not be 
removed or tampered with. 

33. In welding brass or bronze, injurious fumes may be given off, 
making it desirable to wear a respirator. 

34. Smoking while on duty should be prohibited. 

35. Electric lights in a generator house should be enclosed in vapor- 
tight globes protected by the regular guards. 

36. Snap switches shoidd be placed outside of the generator house 
in a suitable place, pi'ovided the house is isolated. 

37. Piping which is used to carry acetylene or hydrogen should be 
painted a distinctive color. 

3S. The manufacturers should provide couplings for the hose which 
cannot be mistaken and put on the wrong hose. If the couplings could 
be made only with the proper connections, it would be impossible to 
make a mistake. 

39. In storage houses where hydrogen or acetylene tanks are stored, 
the wiring should conform to the same rules as for the generator house, 
so that an explosion could not he caused by defective wiring or a 
In'eak in the bulb. 



WELDING SHOP LAYOUT 309 

40. The valves on the piping sliould contain neitlier copper, brass, 
nor l)ronze. 

41. In opening tlie outlet valve of a full tank, do not remove the 
regulator. 

42. The operator should not stand in front of the gages when 
opening the discharge valves on the tank. If the pressure goes off 
suddenly, it may possibly destroy the gage and the glass, and parts 
will be blown out at the front. 

43. A label should be placed on every tank of oxygen, stating that 
it should be kept away from grease. 

RULES FOR WELDING 

The following rules, adopted by the Committee on Standards 
for Locomotives and Cars, U. S. Railway Administration, for 
the purpose of preventing the abuse of autogenous welding 
for purposes for which it is not well adapted, have been sent 
to the regional directors by Frank McManamy, assistant 
director of the Division of Operation, with instructions to 
direct all roads to observe the rules in the construction or 
repair of locomotive boilers, so that any failures which may 
have been caused or contributed to by unrestricted or improper 
use of autogenous Avelding may be prevented. 

1. Autogenous welding will not be permitted on any part 
of a locomotive boiler that is wholly in tension under working 
conditions, this to include arch or water bar tubes. 

2. Staybolt or crown stayheads must not be built up or 
welded to the sheet. 

3. Holes larger than 1-| in. in diameter when entirely closed 
b}- autogenous welding must have the welding properly stayed. 

4. In new construction welded seams in crown sheets Avill 
not be used where full size sheets are obtainable. This is not 
intended to prevent welding the crown sheet to other firebox 
sheets. Side sheet seams shall not be less than 12 in. below the 
highest point of the crown. 

5. Only operators known to be competent will be assigned 
to firebox welding. 

6. Wliere autogenous welding is done the parts to be welded 
must be thoroughly cleaned and kept clean during the progress 
of the work. 

7. "When repairing fireboxes a number of small adjacent 



310 



GAS TORCH AND THERMIT WELDING 



patches will not be applied, but the defeetive part of the sheet 
will be cut out and repaired with one patch. 



1- 



- A?" *-| \< /O" 



J 



x^V 






1 



m 



/5 

J2 



/^ 



IT 



s 



U* /£>■ 



TMieHMesa'<"-P/.ATf 




use 


o'tv^^' 


^/ 


s/ 


ABove Uro g' 


%2 


sy 


AOoye'^To^- 


%? 


s/ 


ABOVe ifTO-C ■ 


%2 


S2 


ABoye Itf' 


%h 


S3 



B£^o^e W/^tof/ve 






D 



? — \ / — \ 



\^60*J 






\. 



D 



Fig. 257. — Kinds of Welds Tested and Examples Used as Welding Guides. 




8. The autogenous welding of defeetive main air reservoir 
is not permitted. 

9. Welding rods must conform to the speeihcations issued 
l)y the Inspection and Test Section of the United States Rail- 



WELDIXC SIIOl^ LAYOUT 



311 



I'oatL Adiiiiiiistralion for the various kiiicLs of work for which 
tliey arc pi-csci'ibcd. 

STRENGTH OF OXY-ACETYLENE WELDS 

The results of tests made by the Welding Committee of 
the Emergency Fleet (*orpoi'ation, on oxy-acetylcne welds of 



4-r)2S 

4-r)29 
4-r)30 



4-r.8i 
4-r):^2 

4-r)33 



Tabi.k XVIII. — Strength of Oxy-Acktylenk Welds 



Mark 


Size- 


Kind of 
Weld 


ritimate 
Strength 


Strength 

Per 
Sq. In. 


Per 

Cent. 


Av. Per 

Cent. 


Break 
In 


1 
2 

3 


I" Sq. 


Butt 


50600 
50235 
49795 


50600 
50235 
49795 


92. 
91. 
90. 


91. 


Weld 


]-m4 

1-513 


]" Dia. 


.. 


43315 

44885 
45160 


55000 
56900 
57400 


100. 
100. 
100. 


100. 


'' 


1-r.n 
i-r)i2 
i-.no 


2" Dia. 


" 


15520 
149515 
153900 


47500 
46800 
48200 


86.5 

85.2 
87.5 


86.4 


» 


2--)! 6 

2-rii7 
2-r)i8 


iXU" 


R. Ang. 


7515 
7645 
7915 


40000 
40500 
42000 


73. 

73.5 
76.3 


74.2 


Bar 


2-.-)! 9 
2-520 
2-521 


:1XH" 


'' 


12605 
12820 
12150 


33600 
34000 
32300 


59.2 
61.5 
59.0 


59.9 


Weld 


B-525 
3-52G 
3-527 


hX}¥' 


Butt 


10890 
10775 
10935 


58000 
57500 
68500 


100. 
100 
100. 


100. 


Bar 

Weld 
Bar 


3-522 
3-523 
3-524 


\xn" 


" 


21460 
22025 
20785 


57000 
58600 
53300 


100. 
100. 
96.5 


98.8 


Bar 
Bar 
Weld 



ixn" 



ixn" 



Lap 



10970 
10725 
10965 



58500 
57500 
68600 



100. 
100. 
100. 



100. 



21905 
22085 
21435 



59300 

58700 
57000 



100. 
100. 
100. 



100. 



Bar 
Bar 
Bar 



Bar 
Bar 
Bar 



5-537 
5-538 
5-539 



.JXU"' 



Tank 



2495 
2210 
2760 



13300 
11750 
12106 



24.6 
21.4 



22.6 



Bar 
Bar 

Weld 



5-534 
5-.535 
5-536 



iXU" 



4936 
5675 
5196 



13100 
15100 
15600 



23.8 
27.4 
24.7 



26.: 



AVeld 

Bar 

Weld 



312 GAS TORCH AND THERMIT WELDING 

various kinds ai-e given in Table XVIII. The 1 and 2 in. bars 
were of machine steel, turned to size before testing. The sheet 
was steel ship plate. The careful engineer will find some rather 
puzzling discrepancies in this table, but it is the best available 
at the present time. The key numbers of the various specimens 
will be found to correspond to the types of welds illustrated 
in Fig. 257. At the bottom of this illustration will be found 
examples used as guides for welding different joints, the thick- 
nesses of the plates and end-spaces being indicated in the table 
just above the examples. The arrows in the illustrations of 
the test welds indicate the direction of pull. 

STRENGTH OF OXY-ACETYLENE WELDED PIPE 

The Linde Air products Co., Buffalo, N. Y., report that 
they made some tests in their laboratory in 1920, to determine 
the strength of welded pipe. These tests were intended to prove 
to a large user of oil pipe from Kansas, that properly welded 
pipe will not break at the weld under pressure. 

According to the report made, the Linde engineers welded 
together two short sections of standard 3-in. iron pipe, threaded 
the ends and screwed on two standard cast-iron caps. When 
the cold water pressure test was applied to the breaking point, 
the top of one of the caps blew out, leaving the pipe and weld 
intact. The undamaged cap and the remaining portion of 
the broken cap were then removed and two extra heavy iron 
caps were screwed on. At a pressure of 6,200 lb. per sq. in. 
one of these caps let go, still without injury to the weld or the 
pipe. Again the uninjured cap and remnant of the broken 
one were taken off and extra heavy steel caps screwed on. 
This time the caps held, but the pipe split and ripped under 
the added pressure upon passing the elastic limit, tearing up 
to, and l^eing effectually stopped by, the weld which refused 
to give. 

The next test was made with 4-in. pipe. Two lengths were 
welded together, the ends threaded and two extra heavy 
standard caps screwed on. In this test one of the cap heads 
blew out at 4,400 lb., which gave a total end pressure on the 
cap of approximately 33 tons, proving that the broken cap was 
not in any respect defective. The weld was not impaired at 



WELDING SHOP LAYOUT 313 

all. After this test it was suggested that an entirely new 
Avelcl with other pipe lengths of the same diameter be tried. 
Accordingly two more lengths of 4-in. pipe were welded, 
threaded and sealed, this time with extra heavy steel caps 
made to withstand a working pressure of 3,000 lb. of air. The 
pressure was applied and the pipe gave way in the threads at 
4,200 lb. In all of the tests the welds held securely. 



PART 1I-THEK3IIT WELDING 



CHxiPTER I 

THERMIT WELDING: ITS HISTORY, NATURE AND 

USES 

The affinity of finely powdered aluminum for oxygen, 
sulphur, chlorine, etc., is such that it is utilized to, effect a 
reduction of metals from their respective oxides, sulphides 
and chlorides.. This was known for many years and is generally 
credited to Frederick "Wohler. About 1894 Claude Vautin 
found that when aluminum in a finely divided state was mixed 
with such compounds and ignited, an exceedingly high tem- 
perature was developed by the rapid oxidation of the aluminum. 
Since fine aluminum will not burn at a temperature below that 
of molten cast iron Vautin and others first heated the mixtures 
in a crucible. The result was that the initial temperature was 
so high at the moment of ignition that the reaction was 
explosive. 

Profiting by the experiments already made, Dr. Hans Gold- 
schmidt of Essen, Germany, discovered a method of igniting 
a cold mixture of fine aluminum and iron oxide by means of 
a barium-jDeroxide fuse which was set off by means of a storm 
match. His first discovery was made about 1895 or 1896 while 
trying to reduce chromium and manganese. Later magnesium 
powder or ribbon was used for ignition purposes, being set 
off in the same way. A mixture of a few pounds of the 
powders was found to burn quickly and the resulting tempera- 
ture was very high. The original patent for the reduction of 
metals, upon wdiicli all his following patents were founded, 
was granted March 16, 1897, the serial number being 615,700. 
Over 40 have been issued since and more are pending. About 
1898 Dr. Goldschmidt made used of his reduction method to 
weld two pieces of iron together. From this time on the 
experiments developed and difficulties were overcome until a 
process was evolved for the commercial use of the reaction 

317 



318 OAS TORCH AND THERMIT WELDING 

for welding and oliici' purposes. Tlie proeess so developed 
was called tlie Thermit process. The company handling- the 
mixtures and apparatus Avas originally known as tlie Gold- 
sehmidt Thermit Co., but in 1918 the lumie was changed to 
the Metals and Thermit Corporation, New York. 

The present Thermit reaction is 8Al+3Fe.,O,=9Fe+4AL03. 
Expressed in weights this is 217 parts aluminum plus 732 parts 
magnetite=540 parts steel plus 409 parts slag, oi-appi'oximately 
3 parts of aluminum plus 10 parts of magnetite will produce 
on combustion 7 parts of steel. The steel produced by the 
reaction I'epresents al)out one-half of the oi'iginal Thermit by 
weight and one-third by volume. 

Commercial Thermit is a mixture of finely divided aluminum 
and less finely divided magnetic iron scale. The aluminum is 
al)out like gi'anulated sugai- and the scale like coarse sand, the 
7'atio ]jy weiglit being approximately three of iron scale to 
one of aluminum. 

According to tlie company just mentioned the average 
analysis of Thermit steel is : 

Carbon 0.0.1 to 0.10 

Manganese O.OS to 0.10 

Silicon 0.01) 1 ,, ().:;() 

Snliiluii- O.o:; to 0.04 

riiosphonis 0.04 to O.O.j 

Ahiminuni 0.07 to 0.18 

Of course to produce a steel of the foregoing composition 
the aluminum and ii-on scale nuist be very pure. For the 
mixture, scale from l>essemei' or open-hearth steel would prob- 
ably come close to meeting commei-cial demands. The average 
tensile sti'ength of a Thermit weld of the foregoing average 
composition is about 61,000 lb. per squai'e inch. This can be 
varied by adding other elements. The ehistic limit is slightly 
more than half this figure, or an avei-age of about 34,000 
]i()inids. 

Temperature and Characteristics.— While the temperature 
of the I'eaction is too high to be measured by a pyi'ometei' 
it can be calculated (,uite accurately theoretically and Pi-of. 
Joseph W. Richards in his hook "Metallurgical Calculations," 
gives it as 2694 deg. C., which is equal to 4881 deg. F. 



THERMIT WELDING: ITS HISTORY, NATURE AND USES 319 

M. Fery, using liis radiation pyrometer, found tlie temperature 
of the stream of steel as it issued from the crucible to be 2300 
deg. C. (4172 F.). Making allowance for the chilling effect 
of the crucible this is probably about right. Considering the 
melting point of steel to be about 1350 deg. C, Thermit steel 
is nearly twice as hot. 

There is absolutely nothing explosive about the present 
Thermit reaction and no danger is incurred in storing it or 
iiandling the material owing to the fact that it takes over 
1300 deg. V. of heat to ignite it. It is for this reason that a 
special ignition powdei- must be used for starting the reaction. 
The ignition powder, however, must be kept away from heat, 
and in pai'ticulai' the box containing it should be tightly closed 
before the Thermit reaction takes place, so as to prevent any 
spark from dropping into it. All Thermit materials must be 
kept dry, for Thermit that has once become wet cannot be 
restored to its original condition by drying. 

Plastic and Fusion Methods. — There are two different 
methods of using Thermit for welding purposes. For con- 
venience these methods may be designated (1) the plastic 
method and (2) the fusion method. The first is used pi-incipally 
for welding together the ends of pipes. Here the pipe ends 
are first machined off so that they will fit snugly together. 
A mold is then placed around the ends, and Thermit is poured 
into tlie mold from a crucible. The Thermit mixture is first 
placed in the crucible and ignited by means of a small amount 
of ignition powder set off by a match. After the reaction the 
molten content of the crucible is poured into the mold and 
around the pipe ends. By pouring from the top of the crucible 
the slag enters the mold first and surrounds and coats the 
pipe ends and the inside of the mold and thus prevents the 
pipe ends from being burned through. This allows the Thermit 
to heat the pipe ends to a welding heat, after which they are 
forced together, causing a slightly upset welded joint. 

The second, or fusion metliod, is the more commonly used. 
In using this method a mold is also used to surround the parts 
to be welded, but the pai-ts must be preheated — usually to a 
red heat — in ordei- to prevent the Thermit being chilled by 
contact with the colder metal and causing an imperfect weld. 
The Thermit to be used is placed in a cone-shaped crucible 



320 GAS TORCH AND THERMIT WELDING 

so made tliat the melted Thermit steel may be rim out of the 
bottom into the mold, thus preventing the slag from getting 
into the mold and spoiling the perfect fusion of the parts. 
In this method it is also necessary to have the parts to be 
v^^elded some distance apart in order to give the Thermit steel 
an opportunity to properly fuse the surfaces desired and 
produce a perfect union. The distance the parts are separated 
depends on the size and nature of the pieces and whether the 
weld is to be made on two separate pieces or is merely to weld 
a cracked place. 

This last method is especially adapted for welding together 
large heavy parts of considerable section, on account of the 
Thermit steel being produced and inti'oduced into the weld 
quickly in bulk and thereby resulting in but one contraction 
throughout the entire mass of metal. Provision to compensate 
for this contraction can always be made, so that when the 
metal cools there will exist practically no strains. "Welds 
requiring as high as 4000 lb. or more of Thermit have been 
completed successfully. A big advantage of the process is that 
huge welds may often be made without dismantling the machine 
or structure, thus saving an enormous amount of labor and 
time in many cases. 

Neither method, however, is commercially or practically 
adapted to welding very small sections or long seams in thin 
sections, which work can be better accomplished by the oxy- 
acetylene or electric welding processes. It should, however, be 
used for welding shafts when the break is in a journal. It is 
interesting to note in this connection that neither the oxy- 
acetylene nor the electric welding processes has proved practical 
for welding trolley rails together. All so-called welded joints 
l)y tliose methods consist merely in welding plates to the rails 
and the joint therefore is never really eliminated. The Thermit 
process, on the other hand, has proved extremely efficient and 
economical for this work, and thousands of Thermit-welded 
rail joints have l)een in service for years in all parts of the 
world. 

Kinds of Thermit Commonly Used. — For commercial weld- 
ing purposes there are now produced three varieties of Thermit 
known as : 

Plain Thermit. 



THERMIT WELDING: ITS HISTORY, NATURE AND USES 321 

Railroad Thermit. 

Cast-iron Thermit. 

Plain Thermit is simply a mixture of aluminum and iron 
oxide, as previously stated, and is used in making pipe welds 
and welding necks on mill rolls and pinions where the Thermit 
is merely used as a heating agent to bring the pipe ends up 
to a welding temperature and the roll and pinion ends to a 
molten state. 

. Railroad Thermit is plain Thermit with the addition of 
I per cent, nickel, 1 per cent, manganese and 15' per cent, 
mild-steel punchings. This grade is used in connection with steel 
welds. 

Cast-iron Thermit is plain Thermit with the addition of 3 
per cent, ferrosilicon and 20 per cent, mild-steel punchings, and 
is used, as its name implies, for welding cast-iron parts. 



CHAPTER II 

MAKING PLASTIC PROCESS WELDS 

Taking up now the various uses of the tlu-ee varieties of 
commercial Thermit we will first describe in detail the butt 
welding of pipe. This is done by the plastic process which 
is especially adapted to welding joints in the pipes in 
refrigerating plants and for high-pressure steam, hydraulic or 
compressed-air pipe lines. It is also applicable to the welding 




Fig. 1. — Pipe-Facing Machine Open to Receive Pipe. 

of superheater units for locomotives. The joints so welded 
are permanent, nonleakable and never require attention, and 
the original cost compares very favorably with that of the 
special mechanical joints of any type used for refrigerating 
or high-pressure purposes. All of the apparatus necessary for 
the work is easily portable, so that the woi-k may be done 
anywhere. 

In preparing pipe for butt welding it is first necessary to 
insure that the ends are cut square. If the pipe is threaded 
the threaded portions will have to be cut off. While the 
ends of the pipe may of course be squared by various mechanical 

322 



MAKING PLASTIC PROCESS WELDS 



323 




a 



324 GAS TORCH AND THERMIT WELDING 

means tlie company handling Thermit makes a small portable 
machine for the purpose, which is much more satisfactory 
to use than anything else. This device is shown in Fig. 1. 
The operation of this machine is so obvious to any mechanic 
tliat further explanation of its operation and method of use 
would be needless, except to say that the crank handle by 
which< the cutter is rotated has a ratchet on it so that the 
cutter may be worked in close quarters. 

If after the pipe ends have been faced off they should 
become tarnished they should be brightened with clean, fine 
emery cloth or a fiat carborundum stone, but in no case should 
the faced ends be touched with a file or the fingers. 




Fig. 3. — Pipe Held in Clamps, Mold Partly Assembled. 

When the pipe ends have been properly faced off, the 
pipe is lined up so that the faced ends will butt squarely 
together and then the mold is put in place. In welding coils 
or bends suitable apparatus should be rigged up to keep the 
pipe in alignment. Where the pipes are close together in 
coils it is usually possible to spring out the pipe to be welded 
so as to permit the adjustment of the mold and clamps. 

A Pipe-Welding Outfit. — A complete outfit for welding pipe, 
less the facing machine, is shown in Fig. 2. In this cut, pieces 
of pipe are shown at A; welding portions of Thermit at B; 
cast-iron mold at C ; at D is the magnesia-lined crucible; E, 
clamps ; F, turnbuckles for clamps ; G, crucible tongs ; H, 
gloves; /, pins for tightening turnbuckle nuts; J, ignition 
powder; K, dark glasses, and L, wrench for tightening nuts 



MAKING PLASTIC PROCESS WELDS 325 

of clamps. Ill order to make the procedure clearer a pipe-mold 
and clamp unit is shown in Fig. 3. Here the pipe is shown 
secui'ely clamped in place with the ends butting together. 
When putting this apparatus in place the clamps are first 
adjusted at an even distance from the ends of the pipe and 
securely clamped. The two tension bolts are then adjusted so 
as to bring an even bearing all around on the pipe ends, but 
care must be taken not to put such a tension on the pipe 
that it will buckle when heated. Just enough tension to hold 
the ends securely is all that is needed. It will be seen that 
v^hile a set of clamps may be used for a number of sizes of 
pipe a mold can only be used for the size for which it was 
made. 

How the Mold is Used. — The loAvcr part of the mold is 




Fig. 4.— Mold Fully Assembled for Weld. 

shown in place, but the top part of the mold is shown at the 
left ready to be put on. The slightly beveled recesses in tlie 
top and bottom parts of the mold are for the pouring gate. 
Before putting the top part of the mold in place care must 
be taken to see that the lower part is blocked up or held so 
as to be in close contact wdth the pipe. Tliis may be done 
by means of wedges, earth or any other means at hand that 
Avill stay in place during the process. AVith the top part of 
the mold in place, as shown in Fig. 4, the operator next pre- 
pares the Thermit for pouring. This is done by placing the 
crucible tongs on the ground convenient to the mold and then 
setting the crucible in the jaws of the tongs. It is very im.- 



326 GAS TORCH AND THERMIT WELDING 

portant that the crucible ])e thoroughly dried before using, 
and if it is a new crucible it is advisable to burn a pound or 
so of Thermit in it and then pour the contents out on dry sand. 
This is the quickest and most convenient way of drying a 
crucible. The operator should have the handles of the tongs 
placed toward him convenient for pouring the metal when 
the reaction is completed. If double tongs are used, as some- 
times is necessary with large crucibles, the helper should stand 
opposite the operator in readiness to help pick up the crucible 
at the proper time, lilue or special glasses should be worn 
to protect the eyes from the glare of the reaction. 

As each size of pipe must liave its own size of mold so 
must the portions of Tlu'rmit be measured out in order to 
have the proper amount for a given size of pipe. This is taken 
care of by the concern making the Thermit, which puts it 
into bags, each containing a certain amount of Thermit suit- 
able for a given welding job. For all ordinary jobs this 
scheme makes it unnecessary for the operator to do any special 
calculating in order to know liow much to use in order to do 
the woi'k and not waste material. 

Placing- and Igniting- the Thermit. — With a bag containing 
the proper amount of Thermit tlie operator poui's about one- 
half into the crucible and the rest in a hand scoop for feeding 
into the crucible during- the reaction. Having therefore one 
part of this portion in tlie ci-ucible and the remainder in a 
scoop he places a half spoonful of ignition powder (barium 
peroxicTe) in one spot on top of the Thermit in the crucible. 
This is set off by means of a parlor match, whicli is applied 
immediately after striking and before the head is burned off, 
to the ignition powder itself or else to another match head 
set into the ignition powder. 

The ignition of the powder in turn starts the Thermit 
reaction. After the reaction is well started the operator adds 
the rest of the Thermit from the scoop, trying to keep about 
one-half of the surface of the molten material covered with 
unburned Thermit, and pouring in a steady sti'eam until all 
the Ther-mit is in the crucible. He sliould tlien immediately 
grasp the crucible with the tongs, obtaining a firm grip, and 
pour the contents into the mold, the slag entering first. The 
pour should be made as soon as the Thermit has reacted and 



MAKING PLASTIC PROCESS WELDS 327 

the slag lias conu' to tlic top. The crucible and tongs are then 
set aside and a short time is allowed to elapse for the Thermit 
mass to bring the ends of the pipe to a welding heat. Shortly 
after pouring the operator should turn the tension nuts enough 
to keep a constant pressure to determine when the pipe begins 
to soften, lie should then wait for 10 to 20 sec., depending 
on the weight of pipe, and then force the ends together by 
means of four quarter turns (one complete revolution) of the 
nuts. It usually takes about 10 sec. from the time the pipe 
softens for it to reach a welding heat, or from 45 sec. to 1^ 
niin. from the time of pouring. 

Removing" the Mold. — After the clamps have been drawn 
up, the mold should be allowed to remain in place for 3 or 4 
min. longei', after w'hich the clamps can be removed and the 
cast-iron mold knocked away from the pipe by means of a 
hammer. The Thermit steel and slag will come away from 
the pipe with the mold and can be knocked out of the mold 
afterward. 

Care must be taken in every case that a complete welding 
portion be used, as only the full measure of Thermit will 
give a good weld. 

It is advisable where joints are being welded in quantities 
to have several molds so as not to use molds continuously 
while hot. It is also advantageous to allow the mold with 
its contents of steel and slag to remain on the pipe for a 
considerable time before" removing. If they can be left 10 to 
15 min. it is all the better. 

It has been found in practice that two men, one facing the 
pipe with the pipe-facing machine and the other doing the 
welding, can complete a weld inside of 10 min. and that it 
is a simple matter for them to make from 40 to 50 finished pipe 
welds a day. 

It must be understood from the foregoing that the slag 
that forms on top of the molten material in the crucible is 
poured into the mold first. As soon as this slag strikes the 
cold pipe and inner surface of the mold it forms a protective 
coating which prevents the superheated liquid steel Avhich 
flows in after it from coming in direct contact with either 
the pipe or the mold. The heat of the entire mass, however, 
serves to bring the pipe ends to the desired temperature. The 



328 



GAS TORCH AND THERMIT WELDING 



method of pouring will be undei-stood from Fig. 5. In this 
cut A shows the slag flowing into the mold and coating the 
pipe and inside of the mold; B shows the slag in the mold 
and the steel following, displacing the slag in the bottom part 




Fig. 5.— Pouring Slag an.l Steel into, the Mold. 




Fig. 6.— Mold for Welding Vertical Pipe. 

of the mold, and C shows the mold abont half full of steel, 
but a film of slag separating it from the pipe and mold. 

The foregoing instructions apply to welding pipe in a 
horizontal position. Vertical pipe, however, can be welded in 



MAKING PLASTIC PROCESS WELDS 329 

essentially the same manner, bnt a special mold is required. 
This mold is constructed in such a way as to divide the 
Thermit-steel collar into two parts, so that it may be readily 
removed from the pipe on the completion of the weld. The 
mold also has a different type of pouring gate, as will be seen 
in Fig. 6. 

The same method used for welding pipe may be used for 
welding bars or rods of mild steel or wrought iron of various 
sizes and shapes, but this method is not applicable to welding 
cast iron or high-carbon steel. For the latter work another 
method must be used. 

Cost and Strength of Pipe Welds. — It may be of interest 
to compare the cost of a Thermit-welded joint with that of 
mechanically coupled pipe, and for this the reader is referred to 
Table I, which was taken from ' ' Reactions, ' ' which is the house 
organ of the Metal and Thermit Corporation. While accurate 
determination of the cost that will cover general practice is 
always difficult there is no doubt about the superiority from 
every standpoint of the Thermit-welded joint where a solid, 
leak-proof and especially strong coupling is wanted. For 
ammonia-pipe or similar installations the solid joint is one that 
every real engineer will recommend. 

As to the comparative strength of a Thermit-welded pipe 
joint the following is taken from a report made by Prof. 
Frederick L. Pryor of Stevens Institute July 10, 1914: 

"Two classes of pipe, standard weight and extra heavy, were tested, 
the sizes selected for each type being 1 in. and 1^ in. Six samples 
each of 1-in. standard, 1-in. extra heavy, ll-in. standard and 1^-in. 
extra heavy were selected for test, three being used for the bursting 
test and three for the tensile test. One specimen was left in its 
original form and two specimens were cut in half and joined together, 
one with a Thermit weld and one with standard-threaded couplings. 
One specimen of each size and type was subjected to tensile and 
bursting tests. Standard-Aveight couplings were used for standard pipe 
and extra heavy couplings for extra heavy pipe, and the welded speci- 
mens were put together by your process. The thickness of the material 
at the weld was afterward determined and found to be about 0.02 in. 
more than the thickness of the pipe for the 1-in. specimens, and about 
0.075 in. more than the thickness of the pipe for the 1^-in. specimens. 
A number of pieces of pipe were measured to check the thickness with 
the accepted standard and eacli specimen was within the tolerance factor. 

"The tension tests were made in the usual manner, except that 



330 



GAS TORCH AND THERMIT WELDING 



a plug was inserted in eacli end of tlie pipe in order to assist tlie 
gripping action in the niaclaine. 



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"The bursting test was made by pumping oil into the pipe under 
pressure, the actual pressure to force the plug into the cylinder being 



MAKINCi PLAyTIC PROCESS WELDS 



331 



deteruiiiied by the dimensions of tlie presstiiv plu^^ and the weight 
on tlie scale l)eain. 

"In tlie tension tests all the piin-s joined l).v couiilings ruptured 
in the root of the thread at the coupling, and the welded samples 
ruptured away from the weld with one exception. 

"In the bursting tests all samples, including those put together by 
couplings and welds, ruptured in the seam of pipe. The location of 
the ruiitures for both the tension and bursting tests are noted in 
Table IT." 

Table II. — ItEsui/rs oi-' Tension and Bursting Tests on Sckew-Coltpled 
AND Thermit-Welded Pipe Joints. 



DIMENSIONS IN INCHES 



Outside 
Diameter 

1" Standard 1.315 

IM" standard 1.660 

I" extra, heavy 1 .315 

l}4" extra heavy 1 .660 



Inside 
)iameter 

1.049 


Thickness 
.133 


1.380 


.140 


.951 


.182 


1.272 


.194 



Ulti- 
Yield mate 
Character Point, Tensile 
of Pipe (Actual), Strength, 
Lbs. (Actual), 
Lbs. 
1" Standard 
Straight. . . 18,000 27,900 
Coupling. . 17,250 20,320 
Welded... . 16,500 26,130 



Approximate Location 
of Rupture 



Burst- 
ing 
Pres- 



Approximate Loca- 
tion of Rupture 



sure, 
Lbs. Sq. In. 

Between grips 1 1 , 580 Center of pipe 

Root of thread at coupling 9 , 260 6" from coupling 
lYi" from weld 10, 560 4" from weld 



V Extra Heavy 

Straight... 19,200 34,730 Between grips 13,510 2" from end of pipe 

Coupling 18,770 Root of thread at coupling 13,310 3" from end of pipe' 

Welded. ... 23 ,jOOO 34,970 8" from weld 14,220 2" from end of pipe 

V/i" Standard 

Straight... 22,300 37,670 Between grips 9,440 7" from end of pipe 

Coupling... 21,380 28,500 Root of thread at coupling 8,050 7" from end of pipe 

Welded. ... 20,930 36,020 At weld 8,460 13/^" from end of pipe 



1 J4" Extra Heavy 
Straight ... 29 , 380 
Coupling... 29,100 
Welded... . 27,800 



50,620 Between grips 12,900 U 2" from end of pipe 

29,100 Root of thread at coupling 12,770 2" from end of pipe 
50,980^ 6" from weld 11,490 1" from end of pipe 



Professor Pryor also at about the same time made some 
vibj-atoi-y tests. The pipe selected \vas l^-in. extra heavy, 



332 GAS TORCH AND THERMIT WELDING 

and each test piece was composed of 6-ft. lengths joined to- 
gether by the coupling or weld. The Thermit welds were made 
in the presence of Professor Pryor by a representative of the 
Thermit comjDany and were regular standard Thermit joints. 
These 12-ft. pieces with a joint in the center were subjected 
to a vibratory motion, the pipe depressed and raised 2 in. below 
and above the center line. The test pipe was filled with water 
under 22 lb. pressure in order to show the first failure of the 
material. Two tests were made of the pipe joined with extra 
heavy screwed coupling and one test of the welded joint pipe. 
The reason only one test was made on the Thermit-welded 
pipe was that the number of deflections on it was about 250 
times the deflections made on the screwed coupling, with no 
sign of any deleterious effect. Both the screwed- joint specimens 
l)roke just outside the coupling in the root of the thread under 
6160 and 3430 vibrations respectively. The Thermit specimen 
was vibrated 1,566,340 times, after which it was removed from 
the test and at the time no injury was apparent. The speed 
of these vibrations was about 225 vibrations per minute. 



CHAPTER III 
FUSION WELDING OF HEAVY SECTIONS 



The method, of welding heavy sections and castings, or 
the fusion method, differs considerably from that used for 
welding pipe joints. For one thing the parts to be welded 
must be preheated to a red heat and also another type of 




Figs. 7 and 9. — Sectional View of Thermit Automatic Crucible and Method 

of Lining It 

Fui. 7. — AA, magnesia stone; BB, magnesia thimble; C, refractory sand; D, 
metcl disk; E, asbostos washer; F, tapping pin. Fig. 9. — Method of lining a 
crucible — AA, magnesia stone; BB, luting of fire clay; C, cast iron crucible cone; 
D, layer of wrapping paper or newspaper. 

crucible is needed. The type of crucible used is shown in 
Fig. 7. This is a conical-shaped, sheet-metal receptacle, or 
shell, with an opening in the lower pointed end. In use this 
is suspended or supported above the gate of the mold by means 
of a tripod, bracket or other support. The metal receptacle 

333 



334 GAS TORCH AND THERMIT WELDING 

is lined witli magnesia tar, a liard-bui'nt magnesia stone being 
set in as shown at A. Tliis has a tiibnhir opening in it into 
which a small magnesia tliimble B is pressed. This thimble 
provides a channel through which the liquid Thermit steel is 
poured into the mold. The object of making the crucible so 
tliat it ^nay be tapped from the bottom is to prevent the slag 
from entering the mold, which is directly opposite to the 
procedure for welding pipe. The hole in the bottom of the 
crucible is closed previous to putting in the Thermit mixture 
by means of the tapping pin F, the asbestos washer E, the 
metal disk D and the refractory sand C. This sand is put up 
in small bags for tlie purpose by the company selling the 
mixture. When everything is ready the Thermit is put into 




Fig. 8. — Tapping a Crucible. 

the crucible and ignited exactly as described for pipe wielding. 
After the reaction the tapping pin is pushed up as shown in 
Fig. 8 and the molten steel allowed to run out into the mold. 

The crucible and the thimble tlirough which the metal runs 
after the reaction are two of the most impoi-tant factors in 
the whole process. The high temperature, together with the 
violent ebullition of the molten metal during the reaction, 
necessitates a lining that is not only mechanically strong but 
of a very high refractory substance. It has been found that 
magnesia-lined crucibles are the only ones that satisfy these 
conditions. 

Life of Lining- Prolong-ed by Patching- With Magnesia Tar. 
— As refractory as this material is, however, the crucibles 
that are used to any extent must be I'elined. Sometimes the 
life of a lining may be prolonged by patching with magnesia 



FUSION WELDING OF HEAVY SECTIONS 335 

tar where needed and then baking it. While any good mechanic 
can scheme out ways to line a crucible in an emergency and 
may use fire clay on occasion the following method is given as 
the best way : 

The magnesia-tar lining material should be heated until 
it becomes plastic. A few handfuls are then placed in the 
bottom of the crucible shell and a magnesia stone imbedded 
in this material, as shown in Fig. 9, and centered over the 
hole. More magnesia tar is then rammed around the stone 
to hold it firmly in place. The cast-iron crucible cone should 
then be placed in position Avith the small projection set into 
the hole in the magnesia stone. The upper part is next centered 
in the shell by means of wedges inserted at equal distances 
along the circumference. The magnesia tar is then rammed 
into the space between the cone and the shell a little at a 
time and tamped hard. On the density or hardness of the 
lining depends the life of the crucible. Special iron tamping 
tools with flat ends should be used. The rammer should be 
pounded well with a good-sized hammer when ramming in 
the lining. Better still is a pneumatic bench rammer. 

Do not put in the material too rapidly, and let it be remem- 
bered that the better and more uniform the tamping the longer 
the crucible will last. 

As the mass nears the top the wooden wedges sliould be 
removed as the lining already in place will hold the cone in 
position. 

The Crucible Ready for Baking. — When completely filled 
and tamped a mark should be made with a piece of chalk on 
the cone and the point opposite to it on the lining, so that 
wdien the cone is withdrawn it may be replaced exactly as 
before. Then take the cone out, exercising care not to disturb 
the lining, place a layer of wrapping paper or newspaper over 
the tar lining, then replace the cone carefully, so that the 
marks previously made come opposite to each other. After 
this put on the crucible ring and lute carefully around the 
top with fire clay to protect the upper part of the lining from 
the heat in baking. It is also well to place damp fire clay 
around the l)ottom of the crucible and inside of the stone for 
the same purpose. 

The crucible is now ready for baking, and for this purpose 



336 GAS TORCH AND THERMIT WELDING 

it should be placed in a suitable oven. The heat should 
gradually be raised until the cast-iron cone becomes red hot 
and should be held at that temperature until all the fumes 
stop coming off from the tar, after which it can be allowed 
to cool gradually before removing from the oven. If the 
crucible is baked too long the lining will appear crumbly and 
the life of the crucible will be very much shortened. Baking 
for too short a time will leave some of the tar in the lining 
and cause a violent Thermit reaction. When cool the clay 
luting may be removed, tlie cone taken out and the crucible 
is ready foi' use. 

Thimbles. — The portion that has to withstand the most 
severe strain of all is the part at the bottom of the crucible, 
or walls of the hole through which the metal is tapped. It 
has to stand the wash and pressure of the weight of the moving 
liquid metal and slag undei' great heat. 

The magnesia stone which is centered in the bottom of the 
crucible and around which the material for lining is packed 
has a tapered hole in the center. The tliimbles are of the 
same taper as the hole in the magnesia stone and are set into 
the latter. When the tliimble is used up (either through 
enlargement of hole or by splitting) it can be knocked out 
and replaced with a new one, so that the full life of the 
crucible may be utilized. Thimbles should be wrapped with 
one layer of uncreased paper before being placed in position. 

Since various amounts of Thermit must be used for dif- 
ferent sized welds the crucibles used must vary accordingly, 
although it is possible on occasion to use more than one crucible 
at a time for a given melt. This is not advisable, however, 
unless necessary. For lining these various sized crucibles the 
Thermit company makes magnesia stones and thimbles in 
certain sizes designated by numbers. The metal cones as well 
as crucibles of a given capacity are also numbered. All of 
the ordinary sizes, as well as the amount of magnesia tar 
needed, are shown in Tabl(> HI. 

The Care of Crucibles. — We have described in detail the 
construction of automatic crucibles to be used in connection 
with Thermit welding, and it might be well to include a few 
words on the proper care of these crucibles. 

They should be very carefully handled, as the lining is 



FUSION WELDING OF HEAVY SECTIONS 



r=; J^l 



M a-> wT .. 






















Shippin 
Weigh 

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Pounds 


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of 

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Require! 

for 
Relining 
Pounds 




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338 



GAS TORCH AND THERMIT WELDING 



apt to erack or Jail out under rough IrcalnK'ul. It is also 
always important that they be stored in a dry place, as the 
lining, being porous, will absorjj moisture, and a moist lining 
will cause violent Thermit reaction. 

After a crucible has once been used, it is not necessary 
to clean it of the slag adhering to the inside, as this is a very 
refractory material itself and can do Jiothing but help preserve 
the crucible if left on. At the bottom, however, in the vicinity 
of the stone and thimble, the slag has to be removed so as to 
clear the opening of the thimble or permit of an old thimble 
being knocked out and a new tliimble inserted. 

Applications of Fusion Welding. — With the construction 
and method of using the automatic crucible in mind we will 



POyRINd GATE 



BASIN TO HOLD SLAG 




PREHEATING GATE 

@= Facing ksFire Sand, ks Fire Clay, IzOround Fire Brick 
H = Loam or Mixture of ?j sliarpSand^ 'j Fire Clay 
^ = Iron Plu<j or Sand Flour Core 
Wl= Frame M^YellowWax 

Fig. 10. — Typical Thermit Mold for Heavy Sections. 

next take up the welding of heavy or solid sections in detail. 
Tn order to make this clear a typical Thermit mold is shown 
in Fig. 10. Witli this illustration to refer to the following 
directions will be readily understood: 

We will suppose that the parts to be welded are those of 
a broken frame. It is best to put tram marks on the two 
sections far enough Imck from the fracture to be outside the 
mold box when it is in place. These are convenient to measure 
from when allowing for the contraction of the Thermit steel 
as it cools. Next cut along the lines of the fracture so that 
an opening of from 1 to H in. is provided. The amount of 
the opening depends on the size of the sections to be welded, 
l)ut in no case should it be less than an inch. If it is a diagonal 



FUSION WELDING OF HEAVY SECTIONS 339 

fracture it is usually best to cut it so as to make as near a 
vertical opening as possible. 

Tliere are various ways of cutting away the metal for the 
opening, such as sawing, drilling and chiseling, but the best 
way is to use an acetylene and oxygen cutting torch. In any 
case the opening should be clear enough to allow the free flow 
of the Thermit. Now clean the ends of the sections thoroughly 
for at least four inches from the opening, so as to expose the 
good, bright metal. Be sure to remove all dirt or grease as 
far back as the mold box will reach, so that when the mold 
is rammed up and heat applied there will be no grease to burn 
out and leave a space between the mold and part to be welded. 

If the oxy-acetylene torch is used for cutting be sure to 
remove all oxide or scale left on the parts by the operation. 
Next make allowance for contraction by setting the parts away 
from each other a sufficient amount to make up for the con- 
traction of the Thermit steel and adjacent parts in cooling. 
This should be varied from | in. to ^ in., depending on the 
size of the weld. In many cases it is necessary to obtain this 
increased space by forcing the sections apart with a jack or 
other mechanical means. In other cases, such as the welding 
of a double-barred locomotive frame, it will be necessary to 
heat an opposite member by means of a flaming burner attach- 
ment on a double-burner preheater or by using a basket fire. 
It is sometimes advisable to construct a small fire-brick or sheet- 
iron furnace around such a section in order to confine the 
heat or protect other parts from the flame. This, however, is 
done only at the time of preheating. 

With the parts lined up and proper allowance made for 
contraction they are ready for the wax mold. 

Wax-Pattern Molds. — The wax-pattern molds are made of 
yellow wax, as indicated in the illustration of a typical mold. 
This wax is placed in a pan and warmed until it becomes 
plastic or else melted entirely and then allowed to cool until 
plastic. Tliis wax is then shaped around the parts to be welded 
in the form of a collar as shown. The opening between the 
ends should also be filled with wax, and it is necessary to 
provide a vent hole through the wax extending from the 
location of the heating gate to the riser. The best way to 



340 



GAS TORCH AND THERMIT WELDING 



do this is to imbed a piece of good stout twine in the wax, 
which can be pulled out after the pattern is formed. 

The mold box, details of which ai-e sliown in Fig. 11, should 
then be placed in position and securely blocked up so that 
all weight will be removed from the sections to be welded. 

We are now ready for the molding material. This should 
consist of one part fire clay, one part ground fire brick and 
one part fire sand. This is used for the facing of the mold 
or the part that comes in contact with the Thermit steel. If 



MATERIAL LIST 
Z Sheets 4e"'df'^ie Iron I Sheef 3Z ■ IZ"-^,^ Iron 

I ■• 4(>:,/d;iib ■■ J •■ zr-if-iX .. 

/ - li; IS ' ^k " I ••„ ,14 '11' l/i ■■ 

/ •■ Z4'/S''^/i • /P-?4-''iBolfsivithlNut 

l?-l6"''i'Bolti wr^h^/iut5 




75- 

c 



Plate D'fo slide 

in Tor t>acl<inqup 

Core o^ tiec ti nq Octe 



X'f'i^ 





■- 33'^ ■ 





Bottom of Box'C'l Req 



Front End Piece A 

for Bo> Tor l?"Molc( 



Si 

End 

For Box for IB'Mold 

I Req \,^, 



Back End Piece B' 

For Box for 16" Mole* 
I Req 



Boick End Piece'B" 

Tor Box for l?"Mold 



Fig. 11. — Design and Materials Kequircd for Standard Mold Box. 



it cannot be obtained in the vicinity it can be ordered from 
the Thermit company. Tliis material should be well riddled, 
nnxed dry and then moistened with just enough water so that 
it will pack well. 

Ramming the Mold.— In ramming up the mold place a small 
amount of molding material in the box and ram with a small 
rammer around the edges and working toward the center, 
keeping the mold level, and ram hard. Too much emphasis 
cannot be laid on this point, for in the construction of the 
mold depends the safety of the entire welding operation. See 



FUSION WELDING OF HEAVY SECTIONS 



341 



to it that the material is well rammed underneath the pattern. 
There should be a wall of molding material at least 4 in. thick 
between the wax pattern and the mold box at all points, as 
the Thermit steel is intensely hot and ample material must 
be provided to hold it. A wooden gate pattern for the pre- 
heating opening should be set at the lowest point of the wax 
pattern and leading out to the front of the mold box, where 
an opening is provided for it. Where the sections to be welded 
together are of the same size this preheating gate should be 
set directly in the middle of the lowest part of the wax pattern 
so as to heat both sides of the frame equally. Sometimes, 



H— ■ 



...... 14' 






-1 



mi 



ji 



7i 



I*: 



PATTERN FOR POURING GATE 

IT W IS 




PATTERN FOR HEATING GATE 



h- 



jf 



PATTERN FOR RISER ' 

Fig. 12. — Wooden Patteins for Pouring Gate, Riser and Heating Gate of 
Alold. These Are Large Enough for Welds Up to 5 X '^ J^"- Larger 
Welds Eequire Proportionately Larger Patterns. 



however, it is necessary to weld a light frame section to a 
heavier one, in which case the preheating opening should favor 
the heavier section, which will require a longer time to heat 
than the light section. 

AVith the preheating gate provided for, set another wooden 
gate pattern directly above it and one inch away from the 
wax pattern and have it properly shaped for the pouring gate. 
Drawings for these various patterns are shown in Fig. 12. 

Be sure that the molding material is Avell rammed around 
these patterns so that it will not "cut out" under the blast of 
the preheater. 



342 



GAS TORCH AND THERMIT WELDING 



At the highest point of the wax pattern place the riser 
pattern. If there is more tlian one liigh point, place a riser 
pattern over each, as the function of a riser is to hold a supply 
of steel wliich will remain liquid for a considerable period of 
time, and take care of all shrinkage, so that when a "pipe" 
is formed, due to shrinkage, this pipe will appear in the riser 
and not in the weld. Also the riser acts as a depository for 
loose sand or other foreign matter that may be washed into 




k Z4" 

dOTTOMFRAML 



>| Section 
Through Trough 



Fig. 13. — Method Employed in Making Welds in Inaccessible Places. 

it by the Thermit steel in passing through the mold and pre- 
vents this material from clogging in the weld. It sometimes 
happens that welds are made at a point where a wooden 
riser pattern cannot be withdrawn conveniently. In such cases 
a piece of jacket-ii'on pipe may l)e used and left in the mold 
after ramming up. The Thermit steel will flow into this open- 
ing and simply melt the iron i^ipe and amalgamate with it. 
After the mold is all rammed up, hollow out on top so as 



FUSION A\l':LDIiNG OF HEAVY SECTIONS 343 

to form a l)asiu in Avliieh tlu- slag' may collect so as not to 
overrun the mold box. Then vent the mold thoroughly by 
making holes with a vent rod nmde from 8 to 10 gage steel 
wire, so that all gases in the liquid metal will have a ciiance 
to escape, as shown in the typical mold. This is important. 

Now lightly rap the gate, riser and preheating opening 
patterns and draw them out carefully, wiping away any loose 
sand that might tend to fall into the holes. A molder's slick, 
trowel and lifter are very useful in this connection. Then cover 
the various openings so that nothing will fall into them and 
adjust the crucible in position with the bottom about 3 in. 
above and directly over the center of the pouring gate. 
"Where this cannot be done, construct a runner, as shown in 
Fig. 13, to lead the steel into the pouring gate of the mold. 

Preheating the Mold. — The mold is now ready for preheat- 
ing. Set the burner of the preheater so as to point into the 
heating gate of the mold and about 1 in. from the opening; 
then apply the blast. It is best to start easily at first, as too 
much of a blast would tend to "cut" the mold. The wax 
will burn out, leaving a perfect mold the shape of the wax 
pattern. Keep the heat going until the mold is thoroughly 
dried out and the parts to be welded are brought up to a 
good, red, workable heat such as would be required if the 
frame was to be hammered. 

AVhile the preheating is in progress the charge of Thermit 
and additions should be placed in the crucible, which is first 
plugged in accordance with the directions previously given. 
It is important to put in a few handfuls of Thermit first before 
dumping in the rest of the charge, so as not to disturb the 
plugging material. Mix the Thermit charge thoroughly before 
putting in the crucible. No ignition powder should be added 
until the Thermit charge is ready to be ignited. If the Thermit 
charge when leveled off comes closer than 2 in. to the top 
of the crucible or if the crucible has to be tipped slightly it is 
best to build up the crucible by means of a ring. This ring 
should be less in diameter than top of crucible so it can set 
in the crucible about 1 in. It should be from 8 to 10 in. high 
and made from ^-in.. stock. Lute with fire clay between ring 
and crucible. 

When it is assured that the frame is at a good workable 



344 GAS TORCPI AND THERMIT WELDING 

heat (luickly remove tlie i)relieater and dii-eet it down the riser 
so as to blow out any sand or dirt that may be in the mold. 
If the riser is difficult of access direct the burner down the 
pouring gate. Then plug the preheating hole with a piece 
of fire brick ground to fit or an iron plug inserted as shown 
in Fig. 10. Back this up with several shovelfuls of molding 
material between the mold box and steel plate provided for 
the purpose and then pack the sand down hard with a rammer. 
This will prevent any possibility of the Thermit steel running 
out through the preheating opening. All heating apparatus 
should be removed to a safe distance while the Thermit reac- 
tion is in progress. 

IGNITING THE THERMIT 

Place one-half teaspoonful of ignition powder on top of 
the Thermit in the crucible (Thermit will not ignite from the 
heat of the preheater and the reaction cannot be started with- 
out ignition powder). Ignite this with a parlor match, apply- 
ing the same immediately after striking, or else ignite with 
a red-hot iron; this often ts the easier method. It is important 
that ample time be allowed for the completion of the reaction 
and for the entire fusion of the punchings, which are mixed 
with the Thermit. It is best to wait at least 35 sec. before 
tapping the crucible. This is accomplished by knocking up 
the tapping pin which sets in the bottom of the crucible, using 
for the purpose the tapping spade or a flat piece of iron l^Xi 
in. by 4 ft. 

Hold up the expansion on the parts with a jack or pre- 
heater until the metal in the weld has set and shrinkage 
commences to set in; then remove the jack or shut off the 
heat. This should be usually done about two or three hours 
after the weld is made, but depends largely on the size of the 
section and length of preheating. 

The mold should be allowed to remain in place as long as 
possible, preferably over night, so as to anneal the steel in 
the weld. In no case should it be disturbed for at least six 
hours after pouring. 

After removing the mold, drill through the metal left in 
the riser and pouring gate and knock these sections off, or else 
cut them off with an oxy-acetylene torch. 



FUSION WELDING OF HEAVY SECTIONS 



345 



Amount of Thermit Needed for Welds. — Tlie amount of 
Tliermit needed for welding sections of different sizes can be 
derived from Table IV, which contains the proper proportions 
of manganese, nickel and pimchings. These amounts are given 
on the supposition that the Thermit collar or reinforcement 
is made in accordance with the dimensions published in the 
table. 



Table IV. — Welding Portions for Welding Rectangular Sections. 



Width of 


Depth of 


Width of 


Thickness of 


Quantity of . 


Section 


Section 


Thermit 


Thermit Steel 


Railroad Thermit 






Steel Collar 


Collar at Center 


Required for Weld 


Inches 


Inches 


Inches 


Inches 


Pounds 


3 


2 


4 


1 


40 


3 


2J^ 


4 


1 


40 


3 


3 


4 


1 


45 


3 


^Vz 


4 


1 


50 


3 


4 


4 


1 


55 


4 


4 


4 


1 


65 


4 


^Vz 


4 


1 


65 


4 


5 


4 


1 


70 


4 


5J^ 


5 


1^ 


75 


4 


6 


5 


iVi 


75 


4}^ 


Wi 


5 


IM 


70 


W2 


5 


5 


IM 


75 


4H 


5H 


5 


IM 


75 


43^ 


6 


5 


1% 


80 


5 


5 


5 


IH 


75 


5 


51^ 


5 


IH 


80 


5 


6 


6 


Wz 


85 


5 


7 


6 


iVz 


90 


5H 


^Vz 


6 


W2 


85 


5H 


6 


6 


VA 


90 


5J^ 


7 


6 


1^ 


110 


6 


6 


6 


IM 


100 


6 


6J^ 


6 


VA 


120 


6 


7 


7 


1% 


130 


6H 


6M 


7 


IY» 


130 


6J^ 


7 


7 


1% 


150 


^Vi 


8 


7 


ik 


160 


7 


7 


7 


IVs 


155 



It is better practice, however, to calculate the amount of 
Thermit needed for a weld from the weight of wax used in 
the pattern and it is advisable anyway to make this calculation 
as a check. 

"Where the quantity of Thermit is calculated from the wax 
great care should be taken to see that the entire space which 
is to be filled with Thermit steel is filled with wax so that 
not only the collar but the space between the sections is filled 
with wax. Then, by weighing the wax before and after the 



346 GAS TORCH AND THERMIT WELDING 

completion of this operation, the difference will be the quantity 
of wax used, and this weight in pounds multiplied by 30 will 
give the proper amount of railroad Thermit for the Aveld. 

It is recommended that railroad Thermit be used in all 
cases, as it is ready mixed with 1 per cent pure manganese, 
I per cent nickel shot and 15 per cent mild-steel punchings. 
This has been found to give the best results for welding 
wrought iron and steel. For convenience railroad Thermit is 
supplied in waterproof paper bags holding 29| lb. of the mix- 
ture, so that one bag to the pound of wax is sufficient for a 
weld. This rule provides ample Thermit steel not only for 
the weld proper, but also for the pouring gate and riser. 

In case the user has only plain Thermit on hand he should 
then allow 25 lb. of plain Thermit to the pound of wax, and 
should mix with this amount of plain Thermit 1 per cent pure 
manganese, f per cent nickel shot and 15 per cent mild-steel 
punchings. In other words, to every 100 lb. of plain Thermit 
add 1 lb. pure manganese, 10 oz. nickel shot and 15 lb. mild- 
steel punchings. These punchings must be clean and free from 
grease or dirt of any kind and not more than f in. in diameter 
by -J in. thick. 

These rules apply only to welds requiring less than 300 11). 
of Tliermit. For welds requiring more than 300 lb. of Thermit 
the usual mixture takes 20 per cent mild-steel punchings with 
the other additions the same. If railroad Thermit is used add 
3j lb. of punchings to each bag. In special eases it is some- 
times advisable to make up a special mixture in order to 
produce a Thermit steel of essentially the same analysis as 
the steel in the parts to be welded. Where the amount of 
Thermit calculated comes to ten bags or more, one of these 
bags may be dispensed with ; that is, instead of using ten bags 
use nine, or instead of using 20 bags use 18, and so on, as 
the smaller percentage of metal required for gates and risers 
makes it unnecessary to use so much of the mixed Thermit. 

Where it is desired to calculate in advance the amount 
of Thermit required for a w^'ld it is first necessary to estimate 
the number of cubic inches in the space to be filled with Thermit 
steel, i.e., the space between the ends of the sections to be 
welded together and the cubical contents of the Thermit-steel 
collar or reinforcement fused around the Aveld. Allow ^ lb, 



FUSION WELDING OF HEAVY SECTIONS 



347 



of railroad Thermit to the cubic inch, and this will be sufficient 
not only for the weld proper but will provide ample metal 
for pouring gate and riser. In estimating the cubical contents 
of the collar the simplest method is to multiply the width by 
the greatest thickness (i.e., the thickness at the middle part) ; 
then multiply this product by 0.7. This will give the average 
area of the cross-section of the collar. If this is then multiplied 
l)y the total length of the collar around the outside of the 
frame and if all measurements are taken in inches the result 
will be the number of cubic inches in the collar. 



},:zoheD.7 J 



■ZorieVA; 




m ^^orie^m 



■Jac/rwrD> 






T 



"^^g 
y^ 



idackforD,> jZorieEEr 



tjack here or here to Line up 
Fig. 14. — Method of Preventing Unequal Stresses When Welding Locomo- 
tive Frames Broken at Various Points. 

Fracture Location Remarks 

Zone A* Heat zone B to get -^iii in. expansion and hold 2 to 3 hours 

after welding. Preheater or basket fire.* 
Zone B* Heat zCfte A to get ?io in. expansion and hold 2 to 3 hours 

after welding. Preheater or basket fire.* 
Zone C, C, or Cj Jack ?i6 in. at C, C, or C,; keep jack in place 2 to 3 hours 

after welding and then remove entirely. 
Zone D or D, Jack ?i6 in. at D or D,; keep jack in place 2 to 3 hours after 

welding and then remove entirely. 
Zone E Cut out unfractured member of splice to clear collar. 

* When heating either Zone A or Zone B the adjiieent pedestal brace or braces 
should be ])ut in place before commencing to heat so as to distribute the expansion 
and not upset or distort the leg. 

Locomotive Frame Work. — The foregoing directions refer 
to the general run of wrought-iron or steel repairs, but with 
only slight variations the same method is followed for locomo- 
tive-frame work. Tlie principal difference is in placing the 
mold or allowing for contraction in various members and not 
in the use of the Thermit itself. In order to make it clear 
where stresses are liable to be set up in a locomotive frame 
the diagram shoAvn in Fig. 14 has been made. T>y a careful 
study of this and the application of the principles illustrated 
a welder should be able to figure out his work so as to produce 
satisfactory results. 



348 



GAS TORCH AND THERMIT WELDING 



The illustrations will be of assistance in planning the work 
on various parts of a locomotive frame. Fig. 15 shows how 
to place the mold, and jacks for welding a broken frame leg. 
With the pouring gate and risers as indicated they permit of 



POURING GATE 




Fig. 15. — Method Employed in Welding Locomotive Frame Broken in Leg. 



'O 



, , „ P0UPIN6 



A 

■^ 3"h- 




(<■ 4" >l 

Section Through ThermitCollar 

This Section applies to 
Frames up fo4'S'ifor 
Dimensions of Collars on 
LarqerFrames see Table 




HEATING GATE 
Section on A- B 




Frame Ready for Mold 
JACK HERE OR HERE TO LINE UP 

Fig. l(i. — Method p]mployed in Welding Locomotive Frame Broken in .Liw. 

a good wasliing action for the Thermit steel, so that any slag 
or sand tliat might be in the mold will be carried into the 
risers. 

Fig. 16 shows how to weld a frame broken in the jaw. 



FUSION WELDING OF HEA\'Y SECTIONS 



349 



Fig. 17 sliOAvs how to wold a frame broken in the splice. 
In this it is best in making the repair not only to weld the 
broken sections together, bnt also to cut ont a piece abont 
1X5 in. of the unbroken member, so the Thermit will flow 
entirely around the broken sections. By making the repair 
in this manner a good, strong job is assured, and if the bolt 
hole is welded up and the two members welded together future 
breakage at these particular points is practically eliminated. 



POURIHG GATE 




Fig. 17. 



-Method of Welding Frames Broken in Splice. Lower Drawing 
Shows How to Drill and Cut the Unbroken Member. 



The only objection that can be raised against this practice 
is the trouble of separating the members in case the splice is 
to be removed or in order to take out or renew a cylinder. 
This objection, however, is not serious because it is only neces- 
sary to drill a line of small holes where the parts are welded 
together and the member can then be removed. When replac- 
ing it is best to cut a keyway where the frame is cut out and 
then bolt together in the same way as when the frames were 
originally assembled. 



350 



c;as ix)Rcn and thermit welding 



Fig. 18 shows liow to weld locoiuolivc luiul I'ings without 
cutting' tlie slu'ets. This nietliod has proved cntii-cly satisfae- 



Tm-!£'''^i RISERS 




k NOT 
T0PqrMUDR/N6 -OPENED UP \ 

M 




^HEATING GATE 
Section Showing Weld,Gates and Risers 



^Tdiam holes,i"deep 
drilled into mudrin5 



Side Elevoition 
Showing Weld 




Section Showing Prepared 
Mold in 01 Stcindcird Mold Box 

Fig. is. — Mold for Welding Mud Eings Without Cutting Sheets. 




Fig. 19.— Thermit Wehl on Mud RinP-. 



tory and many such welds liavo lioen completed and are givinp: 
good service. 

Typical Welds. — Fig. 19 is that of a finished mud-ring weld, 
in Avhich tlie sheets ai'e not cut. 



FUSION WELDING OF HEAVY SECTIONS 351 




Fig. 20. — Fracture in Crosshead Cut Out for Welding. 




Fig. 21. — Weld Louipleted and Crosshead in Service. 



352 



GAS TORCH AND THERMIT WELDING 



Fig. 20 shows a fracture in a crosshoad cut out for welding. 
Fiff. 21 shows the weld completed and the part in service. 



Fig. 2-^. — Weld on Broken lioeker (Shaft Before Machinin^f 

Fig. 22 sliows a weld on a broken locomotive rocker shaft 
before machining. 




'•^s^ii*!!!'*' 



Fig. 2;?. — Repair on Broken Guide Yoke. 

Fig. 23 shows a repair on a broken guide yoke. 
Fig. 24 illustrates two welds in an engine splice. 



FUSION WELDING OF HEAVY SECTIONS 



353 



Fig. 25 is a repaired driving-wheel center. 

Fig. 26 shows details of a crucible holder for frame welds. 

No attempt has hccii made to make the list of ]-epairs on 
locomotive parts complete, but enough has been shown to serve 
as a guide for practically everything that is apt to confr-ont 




Fig. 24. — Two "Welds in Splice of "Frame. 



the practical man. For superheater work, or pipe work of 
any kind, the directions given luider the heading of pipe weld- 
ing will cover all that is necessary. 

As a sort of recapitulation of the foregoing directions, it 
will be well to keep the following "don'ts" in mind when 
getting ready for all locomotive Thermit-welding work. 



354 



GAS TORCH AND THERMIT WELDING 



Don't keep your material and appliances in a damp place. 
Better store them all in a good, dry room under lock and key, 
the foreman in charge of the Thermit work to have the key. 
Better still construct a tool wagon and keep all Thermit 
material in it. 

Don't start to make a Thermit weld unless you have all 
the necessary materials and appliances and the latter in good 
condition. 

Don't neglect to clean the frame tlioronghlv- Be sure to 




Fig. 25. — Weld on Driving- Wheoi Center. 



remove all the grease, paint, etc., and have as good clean metal 
as possible to work on. 

Don't neglect to take care of the contraction that is bound 
to be set up as the metal in the weld cools. If this cannot 
be allowed for by spreading the sections with a jack or other 
mechanical means heat the opposite unl)roken member with 
the other burner of a double-burner preheater fitted with a 
flaming-burner attachment. If this is not available hang a 



FUSION WELDING OF HEAVY SECTIONS 



355 



basket fire of charcoal or coke al)oiit the unbroken member 
and heat until proper expansion is obtained, holding up the 
heat for two or three hours after the weld is poured. It is 
advisable to expand the frame ^/m in. on the average. Cut 
out the frame along the fracture so as to make a clean opening 
1 in. wide. Proportion your wax pattern to the size of the 
frames as shown in the table. 




O 



/ ' loles; from eactiEnci- 



ZP AT TERNS 
MATERIALS^; ,^ , „ 
One Steel Bar - 4 ''^"-^ ij^g" (>j6' lon^ 
Three Set Screws 3'^ -</// 



WROUGHT IRON STEEL CASTING 




Fig. 26. — Dcsiyu for Crucible Holder for Locomotive-Frame Welds. 



Don't use pin grease or wood in place of wax for the collar. 
Pin grease has some sulphur in it and we all know how un- 
desirable the presence of sulphur is in iron or steel. Pin grease 
and wood of course burn out in the preheating, but they leave 
a carbon deposit that will not burn off but will bake on. 

Don't vary the dimensions of the wax collar. Make collary 
of uniform width and thickness on all sides, thus insuring an 



356 GAS TORCH AND THERMIT WELDING 

even distribution of heat. In the ease of welds on pedestal legs 
cutting down the thickness of the collar is poor policy. Re- 
member that the weld is the object and the weld will not be 
perfect if the dimensions of the collar are not the same on 
all sides. 

Don't moisten the molding material too much. Have it 
damp enough to bind under the natural pressure exerted in 
closing the hand. 

Don't use a molding material that runs to slag in the course 
of preheating; if it will not stand the preheating torch it surely 
will break down to slag, as the Thermit steel flows into it, 
and a mixture of slag and steel is not at all desirable and 
furthest from a perfect weld. 

Don 't forget to support the. frame and mold box by means 
of blocks or jacks, as the weight of the rammed mold is con- 
siderable and will sag the frame. 

Don't start off the preheater with too strong a blast. Take 
it easy at the start and increase the air and gasoline as the 
moisture is driven out of the molding material. In this way 
tlie mold will not l)e cut out and a clean-looking job will be 
the result, with no lumps. 

Don't pour the Thermit on a black-hot frame; heat it to 
a good workable heat. 

Don't use crude or fuel oil to preheat the frames. In start- 
ing the burner of a heater using either, carbon is deposited 
orL the frame and prevents a good weld. Heat preferably with 
gasoline and compressed air. If gasoline is forbidden use 
kerosene, but under no circumstances use crude oil or fuel oil. 

Don't be careless in plugging the crucible. Careless plug- 
ging results in premature tapping, and this latter might lead 
to ugly looking or defective welds due to the imperfect separa- 
tion of slag and steel. 

Don't guess how much Thermit to use. Consult the table 
of instructions and you will not go astray. 

Don't use anything but railroad Thermit for welding a 
steel or wrought-iron section. For cast-iron sections use cast- 
iron Thermit. 

Don't add the ignition powder to the charge in the crucible 
until ready to start tlie reaction. It is advisable to suspend 
the crucible in place, charged with Thermit, before starting 



FUSION WELDING OF HEAVY SECTIONS 357 

to preheat. Everything will then be ready for pouring at the 
proper time. 

Don't tap the crucible too soon after starting the reaction. 
On an ordinary frame weld taking from 65 to 100 lb. of Thermit 
permit 35 to 40 sec, to elapse between starting the reaction 
and tapping the crucible. This to insure good separation of 
steel and slag. 

Don't release the spreading bar or jack or take off heat 
too quickly after pouring. It is best to hold up the expansion 
for two to three hours before removing jack or shutting off 
heat. 

Don't remove the mold box too quickly after the pour. 
Let it remain in place over night ; it will insure the frame 
cooling off slowly and naturally. 

Don't forget to gather up all the materials and appliances 
after completing the work. Take them to the room that you 
ought to have for the storage of this material and it will be 
at hand when you want to make use of it again. 

Don't get excited — keep cool. 

Don't take a chance. Be sure everything is right as you 
go along. There is no such thing as luck. 

Also remember that the riser must be 2|X4 in. at the bot- 
tom and 3X4^ in. at the top and not less than 14 in. high 
where clearances will admit. In the case of welds on vertical 
members two risers should be used^ but their total capacity 
need not be greater than the riser for which dimensions have 
been given. The pouring gate must be not less than 1 in. in 
diameter at the bottom, 1^ in. in diameter at the top and 30 in. 
long. Mold boxes should be made of ^/,e,-in. sheet iron, allow- 
ing for at least 4 in. of molding material on all sides of the 
Thermit steel. 



CHAPTER IV 
WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 

We will now take up the welding of crankshafts, mill 
pinions, rudder-stocks and other repairs which must be lined 
up as accurately as possible. It is not necessary to go into 
details as to the exact method of making the Thermit welds, 
as these have already been thoroughly covered. It is merely 
intended to go into the question of allowances for contraction, 
causes of inaccuracies in alignment after welding, effects of 
mechanically preventing the expansion and contraction and 
other possible difficulties. 

Mechanically preventing the contraction of a weld, inten- 
tionally or otherwise, is a common fault in Thermit welding 
and can be prevented only by constant vigilance on the part 
of the operator. Most operators in repairing locomotive frames, 
for instance, will arrange to jack the sections of the frame 
apart or separate them by heating the adjacent members or 
in some similar way to allow for the contraction which they 
know will take place when the metal in the weld cools. When, 
however, the Thermit operator is confronted with the problem 
of welding a shaft or similar part, he will very often make 
the mistake of strapping the shaft as tightly as possible to 
a bedplate or in V-blocks, which will prevent the weld from 
contracting if the clamps are efficient, although actually allow- 
ing I in. or I in. for this contraction. One particularly bad 
case is reported of "preventing contraction" in which an 
experienced operator jacked a heavy steel section of a rudder 
frame apart to allow for contraction in a broken rib 8X4 in. 
and then proceeded to ram the jack up in the mold box. The 
result of course was that the section cracked alongside of the 
Thermit weld and the jack had to be cut in two in order to 
remove it. But in crankshaft welds the usual result of efficient 
clamping to keep the pieces in fine will be the formation of 

358 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 359 

holes ill tlie weld which in all probability will be blamed on 
the Thermit, a new crucible, the breaking down of tlic mold 
or to other similar causes. Such holes can usually be easily 
distinguished from ordinary blowholes by the fact that their 
axes run parallel, or nearly parallel, to the line of the contrac- 
tion which, in the case mentioned above, is the axis of the 
shaft. 

To show how prone operators are to make this mistake 
one operator who ordinarily would carefully release the clamps 
to allow for the contraction of a shaft weld neglected to do so 
in welding a small trunnion on the end of a heavy steel cross- 
head. This trunnion was defective and was replaced by weld- 
ing a piece of 5-in. shafting onto the cross-head. The cross-head 
was laid on a bedplate and the trunnion was set up in position 
on a supporting block and strongly clamped in place. The 
mold was rammed and the weld poured in the usual way with 
the result that lioles, or shrink-holcs, occurred parallel to the 
axis of tlie trunnion. 

Defects That Frequently Occur. — As an illustration of tlie 
formation of these holes prick a small hole in an elastic band 
and then stretch the band. The hole at first is not noticeable, 
but it will be very noticeable if the band is stretched. The 
original hole corresponds with the pores that occur in cast 
metal and the elongated hole is the result of preventing con- 
traction. A similar defect may be caused in a Thermit weld 
by having a riser with too great a flare, as the sand in the 
mold tends to prevent the riser from pulling in toward the 
weld. In this case of course the holes will run nearly parallel 
to the axis of the riser. This kind of defect frequently occurs 
and is difficult to overcome where, for instance, the part to 
be welded is in the crankpin of a shaft and where the slabs 
or throws are quite close together. In such a case if the sand 
is rammed tightly between the slabs it will prevent the con- 
traction of the pin weld, and pull-holes parallel to the axis of 
the pill will be tlie result. 

All of these defects can be corrected or rather prevented 
in one way or another. In the cross-head weld previously 
mentioned as well as all shaft welds, rudder-stocks, etc., the 
lighter part, or section, should be carefully supported on flat 
blocks so that it will be stable without any clamp and so that 



360 GAS TORCH AND THERMIT WELDING 

it can bo moved backward and forward in the line of tlie weld 
withont affecting the alignment. A strong clamp should then 
be set in place to hold the pieces in line while ramming the 
mold, but should be removed from the lighter piece before pre- 
heating and pouring. In repairing a break in a small section 
adjoining two heavy sections it might even be advisable to 
support one or both of the heavy sections on rollers, as their 
weight alone might very likely pull holes in the weld. 

In welding crankshafts it is customary and best to align 
the shafts on V-blocks. These V-blocks are heavy pieces 
accurately machined and slide in a machined slot of a heavy 
bedplate. The V-blocks should be spaced along the slot of 
the bedplate so as to correspond with the journals of the 
crankshaft. Parallel to the main slot of the bedplate and on 
either side of it are smaller slots similar to those in planing- 
maehine beds. The heads of the holding-down bolts are placed 
in these slots opposite the V-blocks and a short bar or channel 
placed across the shaft and clamped down by means of nuts 
on the holding-down bolts. 

The V-blocks should be so placed on the main journals that 
the shaft can slide at least j in. either way parallel to its axis 
without a shoulder or crank throw striking any part of the 
V-blocks. Experience has shown that crankshafts usually 
break in a main journal or in a pin journal close to a crank 
throw or slab, or the break may occur in the slab itself. It 
is usually desirable to line up the shaft with the throws in a 
horizontal position. Let us imagine a shaft with a break in 
one slab or throw close to the pin journal and the shaft lined 
up in V-blocks with the throws horizontal, the necessary gap 
cut out and the wax and mold in place ready to preheat. The 
operator would probably have a great deal of trouble trying 
to allow for the contraction and would probably attempt to 
do this by shifting one part of the shaft about ^ in. along in 
the V-block and would place various-sized shims in the V-blocks 
to allow for the contraction along the line of the slab. 

Inaccuracy of Alignment Explained.^ — It would all be simple 
enough if after pouring the weld the shaft would remain 
dormant until the weld started to contract when the shims 
could be removed from one side and placed on the opposite 
side to allow the slab to contract, but from measurements that 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 361 

have been taken it has been found that immediately after pour- 
ing the weld there is a great deal of force exerted, as thougli 
a jack were placed between the sections that were fractured. 
This is of course caused by the intense heat of the Thermit 
steel conducting into the parts of the sliaft adjacent to the 
weld, causing tlicm to c"s:pand. One might suppose that there 
would be no great force exerted while the metal in the weld 
was molten, but this can be explained by the fact that the 
riser and pouring gate have become sufficiently sluggish to 
hold the more liquid metal below from forcing upward. IIow- 




I*-- '^ -I 









1 1 


/"DiamPin 


< ■ 


tapered 


1 . ^1 1 


rccmcd 


^ 


andfiUed 


;. . .u. ' . 






j i ] 











6"---->i 6Wanted 



Finish all over 



Fig. 27. — Dcsiau of V-BIocks for Weldina" Crankshafts. 



ever, the fact remains that the parts of the shafts arc strongly 
forced apart so as to slightly tilt the V-blocks and raise the 
shaft out of line. 

Tliis may explain why the inaccuracy in alignment is not 
in the direction of the contraction of the weld but almost at 
right angles to it. In a great many cases tliis tendency to 
separate will shift the parts of the shaft horizontally as much 
as \ in. and as the V-blocks resist tliis they are tilted by the 
force and the shaft thrown out of line. 

It may be hours before any considerable contraction sets in, 



362 GAS TORCH AND THERMIT WELDING 

and by this time the shaft has been permanently set out of 
line. Heating the opposite slab will slightly connteract this, 
but not sufficiently, because the heat conducted from tlie 
Thermit steel will expand one slab a great deal more than 
any possible preheating on the opposite slab. 

Crankshafts that are broken in such a way that they can 
be lined up with the throws in a vertical position will be almost 
as far out of line because the sudden expansion of the adjacent 
parts will have to shift part of the shaft and even sometimes 
lift it partly out of the V-blocks, and this force is being exerted 
througli molten or perhaps plastic metal so that a certain 
amount of upsetting will naturally take place. 

V-Blocks for Holding Shafts. — In order to overcome these 
important defects the special V-blocks shown in Fig. 27 will 
allow a horizontal motion after the mold is rammed. If then 
the proper allowance for contraction is made the shaft should 
come back into line because the force tending to separate tlie 
fracture will not be resisted and will be subsequently offset 
by an equal contraction. On the other hand such V-blocks 
will permit of watching the contractions of the shaft so that 
different allowances can be made on the next shaft if necessary. 

These V-blocks sliould be made in such a way that they 
will be divided in two parts horizontally. The upper and lower 
parts should each have divisions, accurately marked on them 
next to the dividing line, tlie central division being longer 
and heavier than the rest. When the two parts of the V-blocks 
are central on each other, accurately turned pins, preferably 
tapered, may be inserted in reamed holes passing through the 
two lugs so as to securely fasten them together. This locates 
accurately the central position where the shaft is to be lined 
up "in line." Where a horizontal contraction is to be allowed 
for, the pin should be left out of certain V-blocks and the 
parts of these V-blocks slightly shifted on each other if neces- 
sary. If the V-block pins are not in place the holding down 
bolts can be relied upon to hold the shaft in a desired position 
during the ramming of the mold. When the preheating is 
started these bolts should of course be removed and the shaft 
allowed to move freely. x\nother advantage of this type of 
V-block is that flat shims can be placed between the halves 
of the V-blocks to allow for different journal diameters instead 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 363 

of placing the shims on ilic slanting face of the V-blocks. The 
thickness of the sliims will of course be just half the difference 
in the diameters of the journals. 

In allowing for contraction of a Thermit weld it must be 
remembered that the actual contraction of the small amount 
of Thermit steel in the space between the pieces is almost 
negligible, whereas the actual contraction of the weld may 




Pig. 2s. — Two-Throw Crankshaft — Fracture Cut Away for Welding. 




Fig. 29,— Two-Throw Crankshaft Welded— Repair Made in 72 Hours. 

vary from \/,,. to V^ in. This is due to the fact that during 
the preheating operation the ends of the pieces at the fracture 
expand or approach each other by the amount of the expansion 
of the adjacent parts by the preheating. For instance, if the 
fracture is opened up I in. to allow for the contraction and 
the expansion of the parts during the preheating approach each 
other almost ^/\ in (perhaps V'ei in. less) the parts should 



364 



GAS TORCH AND THERMIT WELDING 



bo almost exactly in line after welding. In welding large sec- 
tions slightly greater allowances for conti-action should be 
made than in smaller ones, because to bring the fracture to 
tlie proper heat takes a longer time and consequently the heat 
"soaks" further along the parts, causing a greater expansion 
and a greater tendency to close up the distance between the 
fractures. 

A large two-throw crankshaft previous to welding is shown 




Fig. oU. — Fracture iu Web (Jut Away for Wekliug a Crankshaft. 




Fig. 31.— Welded in 6i In. Crankshaft Broken in the Web, 



in Fig. 28. This same crankshaft after welding is shown in 
Fig. 29. A 6^ in. crankshaft broken in the web is shown in 
Fig. 30 and the finished weld in Fig. 31. 

How to Locate Minute Cracks in Crankshafts or Other 
Parts. — In the course of welding crankshafts and other im- 
portant work it is often found that while the part to be welded 
is broken clear through there are other minute hairline cracks 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 365 

near by which are sure to give trouble later. It is probable 
that the strain thrown on the part when the break occurs 
is often sufficient to start these small cracks. They may also 
be caused by strains in the metal from improper treatment in 
the first place, and which may have been responsible for the 
first break. 

In any ease, however they may have been caused, the proper 
thing" to do is to locate these cracks and so weld the parts 
as to eliminate them. As they are many times so minute as 
to be invisible to the naked eye some other means must be 
found to locate them. A very efficient method is to paint the 
entire section with a mixture of whiting and alcohol. The whit- 
ing and alcohol should be mixed so as to form a good white 
paint, but not too thin. This dries quickly and becomes dis- 
colored by the grease or dirt in the very fine cracks, so that 
these cracks show up very distinctly. Since it is the oil or 
dirt in these cracks that causes them to show so clearly on 
the white paint it is not a good method to detect cracks in 
a new piece. The part to be painted should of course be cleaned 
of all the dirt and grease on the surface. It is a conservative 
estimate to say that probably one-third of all crankshafts will 
be found to contain additional cracks other than where the 
break is visible. If these are not found and remedied the 
chances are that they will develop into real breaks later. 

Welding- New Teeth in Large Pinions to Replace Teeth 
Broken Out. — The Tliermit process is coming into more and 
more general use in large steel works and rolling mills for 
welding teeth in heavy pinionS;, as it can be relied on to give a 
permanent, efficient and economical repair in the case of these 
very heavy sections. 

The following instructions cover a method which has been 
in use for several years, and if they are carefully followed a 
satisfactory repair is assured. Many pinions weighing up to 
17 tons have been repaired in this way and are now doing 
service. 

The repairs usually consist of replacing teeth or parts of 
teeth which have broken out. They are peculiar in that the 
tooth is a comparatively small projection on an extremely 
heavy steel casting. For this reason, if the repair were at- 
tempted by the ordinary method, i.e., if the casting were pre- 



366 GAS TORCH AND THERMIT WELDING 

heated at the wekl only as covered in previous instructions 
for making Thermit wekis, the heat would be carried away 
into the castings so quickly, especially during the interval of 
removing the preheating burner and tapping the crucible, that 
in most cases a poor weld w^ould result. Everything possible 
must therefore be done to conserve the heat at the weld, and 
to do this efficiently it is necessary that the whole pinion 
should be heated to a red heat. This may be done by bricking 
in the heaviest part and preheating it by means of oil or gas 
burners conveniently placed while the part to be welded is 
being preheated in the regular way. The Thermit company's 
flaming-burner preheater attachments are admirably adapted 
to this preheating work, as they give an extremely hot flame 
which may be adjusted to suit the conditions. (Vire should 
be taken, however, to bring up the heat slowly, as otherwise 
there is danger of cracking the pinion. 

In making all welds where a relatively small amount of 
Thermit steel is to be added to a heavy steel casting or where 
one or both of the parts to be joined is considerably heavier 
and larger than the Thermit steel part it is necessary to take 
special precautions to secure thorough amalgamation of the 
Thermit steel with the heavier part, especially at the extreme 
edges of the line of junction where in service the greatest 
strain will come. The slightest imperfection at this line of 
junction or extreme flber will cause a tear to start in service 
which will cause a fracture of the welded part. A perfect weld 
on this extreme fiber is made more difficult by the fact that 
the metal in the weld always shrinks a little more than the 
white-hot steel of the pinion due to the slight diffierence in 
shrinkage between molten steel and white-hot steel. It is 
necessary therefore that the fusion be obtained for a consider- 
able depth even at the extreme edge of the Thermit steel. 
Fusion at this point is more difficult because the heat of the 
Thermit steel comes from one side only and not from all 
sides as it does near the center of the weld. 

For all these reasons it is desirable to increase as far as 
possible the surface exposed to the Thermit steel in the width 
cf the weld. This at the same time produces edges or corners 
which melt more readily and thus aid in the fusion. These 
edges may be readily produced by cutting out a groove or 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 367 

slot in the main body of the pinion at the center part of the 
root of tlie tooth broken out. This slot should be half the 




/"or f Pipe. I^- 

Length fosuif 
Height of MM 

W-3"P/pe i;^ 



^ 



Preheater Hose 
,Y Connection 

-£5pace between 
'>; Pip^s filled with 
§ MoldingSand. 



^/Plate 



'^CSteel Plate ^ 



Elevation 



W-Outer Pipe tu protect 
inner Pipe from Meat 
VentHoles ^ ^ X-DiometerafRoll Neck 
to see Roll Ad oXy- These Surfaces should 
NeckandTor[/ jj; ) be well coated with 



TEMPiET IN FORMING NEW TOOTH IN WAX Dftinq Plate V-U~^' -, / q, stronq Silica Wash 

chnnlH Pino \ y ■' 



shouldPIpe 
burn off 

DETAIL or BtrnNEH 




METHOD OFPREHEATINd 
SURFACE OF FRACTURE 



TYPE OF PEMOyABLE PATTERNS 
NECESSITATED BT PODS 



Fig. 





^ 


k- 




Y 


\'Soltibr 
'liftinq 
'iPaftern 


1 


'|a 


i. 


r-'--^-'^"' 



K-— X---» 




PA TTERN FOR ROLL-NECK 
REPAIRING 



xn 



£E 



■FLAME 

Preheating Cope 

if Necessary to use 

H 




Plcinof PartsB 



.'filled with fire Clay 



Hoolf to be used in 5and 
\ Case Pipe'A'should Core 

come loose from , 

Plate: when removinq 

Burner insert Hoolf 

in VentHoles folift 
'' out Plate PLUa FOR OVERFLOW OATE 

Two wanted J 



Bolt 



■Pipe 



32. — Designs for Patterns and Heating Apparatus for Eepairinj 
Steel Pinions. 



width of the tooth in depth and also in Avidth, i.e., if the tooth 
to be welded in is 6 in. wide at its root the slot should be 
made 3 in. wide by 3 in. deep. The most economical way to 



368 GAS TORCH AND THERMIT WELDING 

cut tliis slot is to place the pinion on a planer and machine 
it out. 

The cutting of such a slot also serves to bring the line 
of junction between the Thermit steel and the metal of the 
pinion well into the body of the pinion so that a strong and 
efficient weld is assured. 

After the slot has been cut, the pinion in the vicinity of 
the weld should be carefully cleaned and then mounted 
vertically for the welding operation. In this mounting great 
care should be taken that the pinion is properly supported so 
that there will be no danger of its settling under the added 
weiglit of the mold box. This can be accomplished in the 
following manner: 

First dig a hole in the ground the proper size to receive 
the neck of the pinion. Then lay two T-rails across the top 
of the hole so that they will come underneath the shoulder of 
the pinion. If the ground is not sufficiently hard to properly 
support the T-rails steel plates can be placed underneath in 
order to prevent the rails from settling into the ground. 

Making- the Wax Tooth Pattern. — With the pinion properly 
supported in this manner the next step is to provide the wax 
pattern for the new tooth. This can best be done by con- 
structing a rough wooden box a little larger than the tooth 
in question. Place this against the pinion where the new tooth 
is to be added and lute around the edge of the box with fire 
clay. Next fill this box completely with molten wax. When 
the wax has set remove the box and shape to proper form 
by means of a templet as shown in A, Fig. 32. 

This templet should be made from J^-in. steel plate and 
the outline of the teeth cut into it by using three good teeth 
in the pinion as a guide. The center tooth, however, which 
will be the guide for the tooth to be welded in, should be cut 
V32 ii^- larger all around so as to allow for the contraction 
of the Thermit steel tooth. The two outside teeth of the templet 
engage with the teeth on each side of the wax pattern, and 
therefore wlien this templet is moved up and down it will 
cut the wax to proper shape and also assure that the new 
tooth is welded on in proper pitch. 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 369 

ANOTHER METHOD 

One disadvantage of this method of making the wax core 
is that if the adjacent teeth arc considerably worn the new 
tooth will not conform to their shape unless the templet is 
juggled considerably when shaping the wax pattern. A newer 
method has recently been developed by F. N. Keithley and 
used with success. This method gives a east tooth of the same 




Tooth broken out here 




Scrape offl^ from Sand 

C 



Wax cut up info small Cubes 




Board over Shroud Rin^ 
Clay Luting 




Height of Tooth 



> Length of doard'AlessI/"^ gj^^^/ 

BOARD USED AS BOTTOM OF 
SAND CORE 



^- 



1^ J 



Fig. 33. — Recently Developed Method of Making Wax Tooth Pattern. 

approximate shape as the others in the pinion, even if con- 
siderably worn, which is an obvious advantage. 

Referring to Fig. 33 the broken tooth is slotted out as in 
the previous method and the adjacent teeth are cleaned and 
scraped. AVith the pinion in a horizontal position Avooden 
strips are fitted to the bottoms of the tooth spaces, as shown 
at the left in C. Lag screws are screwed into these for handling 
purposes. Further details of the strips are shown at E. A 



370 GAS TORCH AND THERMIT WELDING 

mixture of two pai'ts building sand to one of tire clay is sifted 
through a No. 4 mesh riddk^ and moistened a little more than 
for ramming a mold. If this mixture does not draw well more 
fire clay may be added. The mixture is pressed between the 
model teeth on top of the board strips, as shown at the right 
in C. The mixture is rammed in firmly to a point f in. above 
the top of the tooth on the side for the wax pattern, as in- 
dicated at C and at F. The idea is to provide sufficient height 
of wax to allow for shrinkage. 

After the two parts are rammed they are lifted out and 
laid carefully on a board. One-fourth of an inch of material 
is then carefully scraped off of the side of each piece that 
does not come in contact with the wax, and the surfaces are 
slicked. This is to allow for shrinkage of both wax and 
Thermit steel. The two pieces are now placed in position as 
shown at D. Weights should be placed partly on the pieces 
and partly on the adjacent teeth to hold the pieces in place. 
The ends are then luted with fire clay and the space filled 
with small pieces of wax. The melted wax is then poured in, 
taking care not to have it too hot, as it will eat into the sand 
if it is. 

The mold parts in position and the wax poured are shown 
at D. If the pinion is shrouded the wax pattern for the shroud 
can be put on at the same time that the wax tooth is formed. 
It is only necessary to roll a clay rod about 1 in. in diameter 
and lay it against the pinion 3 in. away all around from the 
space cut in the shroud. Back this up with a board large 
enough to extend above the top of the tooth and lute as in- 
dicated at B. 

When the wax pattern is finished the mold box should be 
placed in position and securely clamped to the pinion, the 
clamps to be in a position so as not to come in contact with 
the fire when the pinion is being preheated. 

This mold box should be wide enough to take in two teeth 
on each side of the tooth to be welded. Now ram up the mold 
box, allowing for a preheating gate, a pouring gate and a 
riser in accordance with instructions already given. When 
this is completed construct a brick furnace around the exposed 
part of the pinion and about 2 in. away from the teeth. Next 
place a sheet-iron casing around the exposed neck on top. 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 371 

This easing slionld bo 6 in. larger in diameter than the neck 
and about 4: in. higher. Now ram sand between the casing 
and the neck and cover the top with a layer of sand 4 in. thick. 
In this way the entire pinion is insulated. 

Preheating. — The next step is the preheating. Place a 
burner at the bottom of the brick furnace as shown in Fig. 34, 
and start with a very mild heat. This is to avoid lieating 




ElG. 34. — Mold Box, Brick Furnace and Crucible in Position and Pinion 

Being Preheated. 

the pinion too quickly, thus causing internal strains which 
might result in cracking the pinion. After the pinion has been 
thoroughly soaked with heat the fire can be increased to a 
good sharp heat so as to bring the entire pinion to a good 
blood red or about 1200 deg. Fahrenheit. 

While the heating is in progress, as shown in the rear view, 
Fig. 35, place an automatic crucible of the proper size to hold 
the Thermit charge in position over the pouring gate and 



372 



GAS TORCH AND THERMIT WELDING 



charge with tho wokling portion of Thoivmit. Tn case of very- 
large welds it is sometimes necessary to use two crucibles and 
provide two pouring gates in the mold. 

Repairs of this kind usually require anywhere from 350 
to over 1000 lb. of Thermit. 



-O, 





Fig. 



-Rear View fShowiug i'relicating of Body of Piuion in Brick 
Furnace. 



In special cases it is advisable to make up a special steel 
mixture of essentially the same analysis as that of the pinion. 

Continue heating in the brick furnace initil tlie Thermit 
steel has cooled to about the same temperature as the body 



WELDING CRANKSHAFTS, MILL PINION TEETH, ETC. 373 

of tlic pinion, then remove tlie burner from the furnace, take 
oft' a few of the top bricks and fill in betAveen the bricks and 
the pinion with dry sand, thereby protecting the pinion com- 
pletely from the air currents. 




Fig. 36. — Finished Weld, Showing Metal in Pouring Gate and Eiser. 

The pinion should be allowed to cool slowly in this mold 
for at least six or seven days so as to thoroughly anneal the 
metal in the entire piece. The mold can then be dismantled, 
the weld trimmed and the pinion will be ready for service. 
A pinion previous to trimming is shown in Fig. 36. 



CHAPTER V 

WELDING NEW NECKS ON LARGE STEEL PINIONS 
AND OTHER HEAVY WORK 

Frequent breakag'es of heavy pinions in steel plants have 
resulted in the development of a very ingenious adaptation 
of the Thermit process for their repair. Obviously the casting 
on of a new neck entirely out of Tliermit steel would be a 
very expensive operation and it would also be costly and diffi- 
cult to turn up a new piece of steel and weld it on to the 
original section, as the weld would be a very large one to 
make. Experience has shown, however, that the intense heat 
of the reaction can be utilized for the purpose of bringing the 
broken surface of the pinion to a fusing temperature, at which 
time a supply of liquid steel can be poured in from the ladle, 
and this will unite with the original body of the pinion to 
form a new neck thorouglily amalgamated with the rest of 
the piece. 

Briefly the operation consists in constructing a mold around 
the broken section so as to permit of casting on a new neck 
to replace the one broken off. The original section is then 
preheated to red heat by means of gasoline or oil burners, 
after which Thermit steel from a crucil)le is allowed to flow 
over the fractured surface to a depth of 1 in. This completes 
the heating operation and brings the surface of the roll to 
the melting point. A supply of liquid steel from a ladle is 
then tapped into the mold and allowed to wash through and 
overflow into an ingot mold so as not to be wasted. The 
overflow gate may then be closed and the mold filled to the 
top with steel. Detailed instructions for these various opera- 
tions follow, but it is recommended that if the process is to 
be used for the first time for such repairs an experienced 
engineer should be obtained to supervise the first welds and 
give personal instructions for executing this class of work. 

374 



WELDING NEW NECKS ON LARGE STEEL PINIONS 375 

Tlic iiistruetions given here liavc been written more especially 
for the purpose of acting as a guide for a reference, and while 
we hope that there are sufficiently adequate and complete to 
enable anybody to make these welds, the personal supervision 
and instructions of an experienced engineer are much to be 
preferred. 

Two Methods of Working. — We give two methods for 
executing these repairs. The first method which follows is 
undoubtedly the safest and surest method to use, but it involves 
considerably more trouble and expense than the second method. 
We can recommend it strongly, liowever, and believe it would 
be to the interests of steel plants having much of this work 
to do to equip themselves properly to follow out this, method. 




Pig. 37. — Sawing Off End of Neck Previons to Welding on a New One. 

Before imdertaking a pinion repair the broken end should 
be cut off square, as shown in Fig. 37, so as to form a level 
surface when the roll stands in a vertical position. The object 
of this is to permit of a uniform covering of Thermit steel 
over the entire surface to be welded. If the break is in the 
pods, cut off 2 in. below the point where the pod joins the 
neck. If when the neck is cut off it should be found to contain 
any pipes or cavities these should.be bored out and steel plugs 
turned to a driving fit and driven into the cavities at least 
5 in., care being taken that the plugs are driven in even with 
the surface on the end of the neck. 

Another and better method is to dry out the inside of the 
cavity by heating and then fill with liquid steel. This will 
eliminate any danger of the Thermit metal melting the plug 



376 



GAS TORCH AND THERMIT WELDING 



and running into the cavity, which might cause a violent and 
dangerous eruption of the steel. Clean off all dirt and grease 
at least 20 in. from point of weld. 



FROM FUCLTANK 




FROM FUEL TANK >«'<tj.T _ 



Se c + 1 on A-A 

Foy^dotion to su't condition of ground etc 
In oil cases see "Tiotmo^oi 'S supported 
oriroii independent of f loon 
_ 5ize and nu-Ti her of mold boxes +OSUI+ roll 



Hole fobeplugqed after 
' Thermit sfeel is wGshecf out 



I "STFFL PLATE 




Pig. 38. — A I^esign for a Permanent Pit for Welding Necks on Large 
Rolls and Pinions. If Desired a Removable Fire-Brick Partition May 
Be Used Between Roll or Pinion Pit and the Ingot Mold Pit. 



A riser pattern should be provided, undercut as shown in 
Fig. 32-D, also a pouring gate and overflow gate pattern. 



WELDING NEW NECKS ON LARGE STEEL PINIONS 377 

The riser pattern should be 3 in. larger in diameter than 
the pinion neek, and at the lower part, where it joins the neck, 
it sliould taper as shown. Where the operation requires the 
easting of pods a special pattern should be made having the 
shape of the pinion neck with these pods. This pattern, like 
the riser pattern mentioned before, should be larger in diameter 
than tlie pinion neck and should taper at the bottom. TJie 
pattern should, if necessary, be made in sections so as to allow 
of being Avith drawn from the mold. 

Foundation and Heating Arrangements. — Heavy circular 
cast-steel mold flasks should be provided, the same as are used 
in steel-foundry practice. In the absence of these flasks suit- 
able ones can be made of :|-in. steel plate. The bottom flask 
sliould be divided and bolted togetlier so that it can be removed 
without trouble, as it is much easier to tear down the mold 
after this flask is removed than before. 

In undertaking repairs on these pinions it is recommended 
that a special pit be constructed as shown in Fig. 38. It is 
of the utmost importance when constructing the pit to provide 
a good foundation for the bottom of the pit. It has been 
found in many cases that steel plants are built on low and 
marshy ground, therefore when a pit is dug the ground is apt 
to be soft and many times water seeps in. For this reason 
the design in Fig. 39 is shown. However, unless precautions 
are taken to provide a good foundation heavy pinions are apt 
to settle before the welding operation is completed. This is 
liable to cause a loss of the repair and sometimes a serious 
explosion might result caused by the hot metal coming in 
contact with moisture. When an adequate foundation has 
been provided set the pinion and the ingot mold in place and 
brace them strongly to the sides of the pit. 

Arrange the heating burners which may use gas, gasoline 
or kerosene. This arrangement is shown, although the com- 
plete connection to the fuel supply is not. 

Constructing the Mold.— Construct the mold, as shown, of 
sharp silica sand and fire clay. The usual proportions of the 
mixture are three parts of sand to one of clay, but tliis varies 
according .to the sand and clay used. Coat the mold with a 
good steel wash and drive in nails or chaplets to hold the sand 
in position. 



378 



GAS TORCH AND THERMIT WELDING 



Attach the runners at the proper points and ram them with 
the same material, being careful to arrange the runner for 
the Thermit exactly as shown, that is, the runner gate is so 



rROM FUELTANK 




FROM FUEL TANK 



Sec + ion A 

Hole lobe 

1 'rafter I her nvt 
I ll steel I i 
Hji* washed 



roundation to su't 
condition of ground etc 
nail ccses see that 
mold IS supported on 
roll independent of -floor. 
Size end number of mold 
boxestosuit roll 




Fig. 39. — Method of Welding Roll Necks Without Digging a Pit. 



placed that when the Thermit steel has run into the mold 
the top surface of the neck will be covered with superheated 
Thermit steel to a depth of about 1 in., and the slag from 



WELDING NEW NECKS ON LARGE STEEL PINIONS 379 

the Thermit reaction will flow from the crucible and run out 
of the V-shaped notch in the side of the runner, thereby 
preventing any slag from entering the mold. 

The overflow runner shquld have sufficient pitch so that 
the liquid steel will flow to the ingot mold readily without 
spattering. Firebricks should be laid on top of the ingot mold 
in order to prevent steel from spattering at that point. 

When the mold is completed start the preheating of the 
body of the pinion. If gasoline or kerosene is used three 
double or five single preheaters will be required and another 
one should be kept filled and ready to be cut in when any 
one of the others has become empty. This will prevent loss 
of heat while a preheater tank is being refilled. 

As the body of the pinion approaches a red heat start 
the preheating cf the top of the neck as shown in Fig. 32-B. 
Heat this surface to a good red heat, timing the operation 
so as to have both neck and body of pinion red hot at the 
time the openhearth steel is tapped out of the furnace. 

While the preheating of the neck is progressing set the 
automatic crucible, size 7, charging it in accordance with 
previous directions, so that it will be ready when needed. 

Amount of Thermit Required. — In calculating the amount 
of Thermit required for this type of repair allow 75 lb. of 
railroad Thermit for each square foot of surface it is desired 
to melt down. 

Be sure that the cope has been baked while the preheating 
of the neck is going on (either in an oven or as shown in 
Fig. 32-H) and is located conveniently so that it can be brought 
up with the crane at the proper time. After the furnace is 
tapped raise the ladle of steel and try the stopfer by making 
a couple of pours to be sure that the stopper ^vorks properly 
and will shut off tight. 

Move the ladle to a point near the mold so that no time 
may be lost between pouring the Thermit steel and washing 
through the steel from the ladle. Remove the preheaters to a 
safe distance. 

Ignite the charge of Thermit in the crucible, and when the 
reaction is over (usually 35 to 50 sec.) tap the Thermit steel 
into the mold, as shown in Fig. 40. When all the steel from 
the crucible has flowed into the mold the slag will commence 



380 



GAS TORCH AND THERMIT WELDING 



to run over the V-shaped notch in the pouring runner. Move 
the crucible out of the way and plug the pouring gate with 
a sand core provided for this purpose, banking up securely 
behind it to, prevent leakage. 

Lower the ladle of openhearth steel, shown at the left, 
to a point close to the top of the mold and tap the steel into 




Fig. 40. — Welding a Roll Neck. Thenuit 8teel Tapped into Mold and 
Ladle of Steel at Left Ready for Final Operation. 

the mold, running through about 5000 lb. into the ingot mold 
which has been set for the purpose, as shown. 

Plug the runner gate with a core constructed as shown in 
Fig. 32-J and bank up well behind it so that there will be no 
danger of a runout. Be careful in plugging this gate on account 
of its size. After the plugging is comi)leted and banked up, 
the sand should be weighted down as an extra precaution to 
prevent accident. 



WELDING NEW NECKS ON LARGE STEEL PINIONS 381 

After the overflow has been securely plugged fill up the 
mold with steel from tlie ladle and cover it well with dry 
sand or charcoal to keep the metal hot. 







W 


^^ 


b 


^V^**c~~ 


->~*-, ~ 


"■'~"\ 


-_^ 


in^ 


In 


m 






li 


^^^<.'^^S 


y 


■ 


■ ■ 


' ' ^' " 


"* 




-^ 




'"' 


Bmi^ 



Fig. 41. — Eoll Neck Welded to Large Steel Roll with Pods Cast in. 

Treatment When a Cope is Used. — If a cope is used clean 
off the surface of the top of the mold and set on the cope,~ 
clamping it securely, and then fill the cope to the height desired 




I'iG. 42. — New Neck Welded to Large Steel Pinion. In this Case the Pods 
Were Milled Afterward. 



with steel and again cover over wdth dry sand or powdered 
charcoal. 

If the body of the roll or pinion has cooled to any extent 
it would be desirable to again preheat it. After the body 



382 



GAS TORCH AND THERMIT WELDING 



of the pinion is sufficiently preheated cover the pit to make 
it as nearly airtight as possible, so as to cause the roll or 
pinion to cool slowly. By doing this further annealing is 
unnecessa;'y. 




Fig. 43. — Worn Pods Bnilt I^^p with Thermit Steel. The Repair Consisted 
of Four Wehls Made Simultaneously, using Two Pouring Gates and 
Two Crucibles. 






Fig. 44. — Building Up Worn Pods by Means of Three Thermit Welds, 
Pouring Gates Were Connected at Top and Bottom to Insure Equal 
Distribution of Metal. 



After the pinion is sufficiently cool (usually about 48 hours 
or more) remove from tlie mold and machine to size. 

In some steel plants it is considered preferable not to use 



WELDING NEW NECKS ON LARGE STEEL PINIONS 383 

a cope but to build the mold all in one piece to the height 
of the new neck. This method simplifies the making of the 
mold and the pouring of the weld, but sometimes complicates 
the operation for the following reasons: 

When riser patterns are withdrawn it is a little more diffi- 
cult to remove loose sand from the mold. 

In preheating it is not so easy for the operator to see what 
he is doing. 

There are times when these necks will be as much as 5 ft. 
high, which makes it a little unhandy to work around the mold. 

There are numerous arguments on both sides of the ques- 
tion, but we feel that either method will give good results. 
For short necks, however, a cope can probably be dispensed 
with without introducing any difficulty. 

Two welding jobs just as they came from the molds are 
shown in Figs. 41 and 42. The first is a neck welded onto 
a large steel roll with the pods cast in. The second one shows 
a new neck welded to a large steel pinion. In this last case 
the pods were milled out afterward. 

Two other welding jobs are shown in Figs. 43 and 44. These 
both illustrate the repair or replacing of worn pods on heavy 
steel mill pinions. 

Alternative Method.- — While the preceding directions cover 
the welding of pinions under what might be considered ideal 
conditions it is not always possible to do the work in this 
way, and where such is the case we M^ould recommend that 
the following directions be followed, as they represent a 
simpler method, yet one which has always resulted in satis- 
factory repairs. 

Patterns, mold box, runners, etc., should be constructed 
in accordance with directions given for the previous method. 

In these repairs great care should be exercised in supporting 
the pinion so that there is no danger of its settling under the 
added weight of the mold and the steel which is poured into 
it. If it is not desired to go to the expense of constructing 
a special i^it as outlined in the previous method a satisfactory 
and economical way is to dig a hole in the ground about 8 ft. 
in diameter and of sufficient depth to receive at least f of the 
entire length of the pinion. Cover the bottom of the hole by 
laying a double flooring of 2-in. planking, being careful that 



384 



GAS TORCH AND TPIERMIT WELDING 



I lie planks in one layer run in opposite directions to those of 
the other layer. 

On top of this place a steel plate in order to distribute the 
weight of the pinion over the entire floor area. Such a founda- 
tion has ahvays proved adequate and is not expensive. 








ection 
A-A l^ 

Foundatioh +o suit condition of 
r^-^ ground etc In all cases see that 
'■ mold IS supported on roll independent 
of -Floor Size and number ofrnold 
boxes to suit roll. 

Mo/e fo be plu(^qecl eifter 

'~~^' Ihermitsfeel IS washed ouf 



RUNNER TO 
INGOT MOlD 



•■'y//yy/////y:^^/^}/y}////y/y'^/y^ 



Fig. 45. — Alternate Method of yuppoitiug Roll or Pinion to i>e Iicpaired. 

Set the pinion in the hole so that the surface to be welded 
'\i level and fill in all around the pinion with dirt, ramming 
hard to hold the pinion permanently in position. 

Dig a second hole alongside of tlie buried pinion to receive 
the ingot mold. Tins should be at such a distance fi-oni the 
pinion that a suitable runner for the overflow steel can easily 



WELDING NEW NECKS ON LARGE STEEL PINIONS 385 

be placed. Tlie top of the ingot mold should, of coiirse, be 
lower than the top of the roll or pinion neck. 

If the neck is broken off: close to the body of the pinion 
it is absolutely necessary to provide arrangements for pre- 
heating the body protruding above the ground in order to 
avoid shrinkage strains. A simple way to do this is to build 
up a brick furnace and heat in accordance with directions 
relating to casting of teeth in large pinions, and more of the 
pinion body should protrude above the ground than shown in 
Fig. 45. If, however, there is one foot or more of neck pro- 
truding from tlie body of the pinion, it is not absolutely neces- 
sary to preheat the rest of the j)inion. 

THE MOLD BOX 

Tlie mold box should be constructed with heavy steel flasks 
or a substitute made of at least ^J-in. plate and should be 
supported entirely on the roll and independent of the ground. 




Fig. 46. — Finished Weld on Anchor Davit of U. S. S. " Ohnnpia. " 

With the mold box adjusted in place ram up witli good 
molding material in accordance with the previous directions 
and then draw out the various wooden patterns. Nails or 
chaplets should be driven into the sand so as to hold it firmly 
in place. It is advisable to coat the mold Avith a good steel 
wash. AVhen the mold is completed the preheating of the 
body of the pinion should be started if the repair is of such 
a nature r,s to require this preheating. If this heating is not 



386 



GAS TORCH AND THERMIT WELDING 



necessary start preheating on top of the neck as shown in 
Fig. 32-B. If the body of the pinion is heated the heating 
of the neck shouki not be started until tlie pinion approaches 
a red heat. 





Fig. 47. — Anchoi- of the Morgan Yacht "Corsair''' 
Rciiaivcd with Tlicrniit. 




Fig. 4N. — Weld jn VVlu-ol Nhat'f Of steamer "Nashville" on 
the Cumbcrlanil River, Made in 1912. 

Heat the surface on top of the neck to a good red heat, 
timing the operation so that it will be red hot at tlie time 
the openhearth steel is tapped out. 



WELDINCx NEW NECKS ON LARGE STEEL PINIONS 387 




Fig. 49. — Weld on lO-in. Wheel Shaft of Steamer ' ' Osceola, 
Made at Jacksonville, Fla., in 1915. 




Fig. 50.— Weld on Sternpost of Tug No. 32, Made September, 1911. 



388 GAS TORCH AND THERMIT WELDING 

AVhilo tlic prolicating of the neck is progressing set an 
automatic crucible, size 7, as shown in Fig. 45, and charge 
it so that it will be ready when needed. If possible it is best 
to support the crucible with a crane so that it can be quickly 
removed after it has been tapped. The procedure is then the 
same as described for the previously given method. After 
cooling, strip the mold and machine the parts to proper size. 

It is sometimes desirable where tlie l)ody of the pinion 
has been preheated to continue this heating after the weld 




Fig. 51. — Stcrnpost Weld on the "William Henry Mack," July, 1912. 



is completed. This can easily be done by again igniting the 
burners directed into the brick furnace. After the body is 
sufficiently preheated remove the burners and fill in between 
the bricks and the pinion with dry sand so as to cause slow 
cooling. By doing this further annealing is unnecessary. As 
previously mentioned, a cope may or may not be desirable, and 
this is left to the judgment of the operator. 

Marine Work. — The general principles to be followed in 
making marine repairs are the same as for any other repairs 
of a similar size and nature, so no detailed description need 



WELDING NEW NECKS ON LARGE STEEL PINIONS 389 

be given. Ilowever, it will be of interest to know the exact 
natui'e of some of the more common repairs made on anchors, 
\\ heel shafts, sternposts or the like, so a few views of some 
of the actual repairs are shown. A big point in favor of the 
Thermit process in cases like the ones given is the short time 
necessary for the ship to be laid up. In many cases little 
or no dismantling is necessary. In a number of stern shoe 
welds on lake steamers the sizes of the parts at the break have 




Fig. 52. — Another Sterupost Weld. S. S. "Corumia" of the Canadian 
Lake Transportation Co., Made in 1907. 



been from 11X16 in. to 10X20 in. or more, and the average 
time required has been about 36 hours complete. On a large 
number of ocean-going vessels the welds made have been on 
sections of larger dimensions than those quoted. 

In Fig. 46 is shown a weld on the anchor davit of the fam- 
ous U. S. S. "Olympia." Fig. 47 shows a repair on the anchor 
of the Morgan yacht "Corsair." Fig. 48 is a repair on the 
Avheel shaft of the ''Nashville," a Cumberland River steam- 
boat, made in 1912. Fig. 49 shows a repair on the wheel shaft 



390 GAS TORCH AND THERMIT WELDING 

of the river steamer ''Osceola," welded at Jacksonville, Fla., 
in 1915. Fig. 50 shows a sternpost weld on a tug, made in 
1911. Another sternpost weld is shown in Fig. 51. Still 
another very similar weld is shown in Fig. 52. These are 
sufficient to give the reader a good idea of the application 
of the process to this class of work. 



CHAPTER VI 
RAIL WELDING FOR ELECTRIC SYSTEMS 

Pr()l)ably no problem in recent years has received more 
consideration at the hand of traction companies than the 
snl)ject of track construction and maintenance. Progress along 
this line has been continuous and expense has not been spared 
to obtain the best roadbed possible ; heavier rails are being 
used and particular attention is paid to the foundation, ties 
and drainage ; everything is of the best material and work- 
manship until it comes to joining the rails together, and here 
there usually develops the weak point of the entire system. 
This refers to the mechanical joints in common use. No matter 
how much care is taken in applying splice bars mechanical 
discrepancies and disadvantages cannot be overcome ; the rail 
sections are seldom uniform and the American Society for 
Testing Materials has adopted specifications which limits a 
maximum difference in height to ^/g^ inch. Variable height 
in new rails is often unavoidable, as joint plates fitting one 
rail perfectly may not fit its neighbor. 

There are many reasons why the mechanical joint fails to 
fulfill its function, which are not necessary to enumerate here. 
On the other hand the advantages of a welded rail joint, where 
circumstances will permit, are plain. AVhile there are several 
systems by which rail joints may be welded, at the present 
time the Thermit method is the only one that absolutely 
eliminates the joint. It also has advantages in the modified 
joint-welding woi-k. These advantages will become clear as 
our description of the actual processes develops. Briefly, the 
weld is accomplished by pouring the superheated steel obtained 
from the Thermit reaction into a mold surrounding the rail 
ends at the joint. This fuses ^^^th the base and web of the 
rail as well as with the lip and one side of the head. An insert 
cut from a rolled section of similar analysis to that of the 

391 



392 GAS TORCH AND THERMIT WELDING 

rail itself is placed Ijetween the heads at the running face, 
and the lower part of tliis insert is melted into the Thermit 
steel. The mold is so constructed, however, that the head 
of the rail and the top part of the insert are not melted but 
are merely heated to a welding temperature, so that when the 
Thermit metal begins to cool and contract, thus drawing the rail 
ends together with tremendous force, the squeezing action 
on each side of the insert thoroughly butt welds it into the 
head. When this has been accomplished the running face is 
ground to a true surface and the surplus metal ground out 
of the groove. The weld obtained in this way is so perfect 
that it is practically impossible to detect its location after 
the rails have been paved in. 

In practice the welding is best done after the ties have been 
concreted. If the welding is done before the concreting it is 
somewhat difficult to keep the rails in perfect alignment and 
to proper surface after the temporary splice bars have been 
moved. The rails are spaced f in. apart and must be thoroughly 
cleaned for a distance of 4 in. from each end. This can be 
accomplished by using a small steel-wire brush. The ends of 
the rail heads must next be cleaned and where necessary filed 
smooth so that when the insert is fitted the maximum amount 
of contact surface will be obtained. In other words the insert 
must be made to fit accurately. Following this the rails are 
brought to proper surface and alignment, care being taken 
to keep the rail ends a trifle high, so that when a straightedge 
about 30 in. long is centered over a joint there will be a space 
of about ^/oo in. between the ends of the straightedge and 
the surface of the rail directly under it. This slight raising 
of the rail ends has been found necessary in practice, as it 
assures proper alignment and surface after grinding. 

PLACING THE INSERT 

The joint is now ready for the placing of the insert, as 
shown in Fig. 53. Various thicknesses of inserts must be 
kept on hand to fit the variation in gap brought about by 
temperature changes and other causes. With the inserts in 
position two part sand molds are applied, as shown in Fig. 54. 
these are rammed in advance on a foundry squeezing machine 
over a wooden pattern, the dividing line of the molds being 



RAIL WELDING FOR ELECTRIC SYSTEMS 393 




Fig. 53. — Adjusting Insert Between Bails. 




Fig. 54. — Adjusting Two-Part Mold to Eails. 



394 



GAS TORCH AND THERMIT WELDING 



in the center of the web. A squeezing machine being used 
for this purpose is shown in Figs. 55 and 56. 

The pattern is so constructed as to form an opening around 
the rail ends in the shape of a collar into which the Thermit 
steel is poured. This collar is usually about 3 in. Avide and 




Fig. 55. — Eaniniing Molds on a Squeezing Machine. Wooden Patterns and 
Sheet-Iron Mold Box in Foreground. 



varies from ^ in. to | in. in tliickness, depending on the rail 
section to be welded. Pouring gates and risers are also pro- 
vided for in the mold in a similar manner to those already 
described. 

Recent improvements in the construction of the molds used 



RAIL WELDING FOR ELECTRIC SYSTEMS 



395 



have been perfected to guard against runouts. A bead pro- 
trudes around certain parts, so that when the two halves are 
clamped together it is compressed between them and forms 
a safeguard against tlie liquid steel running out. 

Before clamping the molds to the rails two cords of asbestos 




Fig. 56. — Cutting Heating Gate in Mold. Finished Mold and Wooden 
Pattern Shown in Foreground. 



soaked in molasses are applied around the contour of the rail, 
one on each side of the joint, as shown in Fig. 57, and placed 
in such a position that they will come just inside the outer 
edge of the mold box. The molasses is sufficiently sticky to 
make these cords adhere tightly to the rail and form a very 



396 



GAS TORCH AND THERMIT WELDING 



efficient luting all around the outside edge between the mold 
and the rail. As an additional precaution a small amount of 
fireclay is blown into the mold through the pouring gate by 




Fig. 57. — Applying Asbestos and Molasses Strips to Rails Previous to 

Placing Mold. 




Fig. 58. — Fijial Luting Process, Blowing Powdered Fire Clay into the Mold. 

means of compressed air, as shown in Fig. 58, while the other 
openings are closed temporarily by inserting wooden plugs. 
Should there be any opening around the edges of the mold 



RAIL WELDING FOR ELECTRIC SYSTEMS 



397 



the fire clay escaping tlirough that opening will he caught 
by the molasses on the asbestos cords and the opening auto- 
matically sealed. When the air-pressure gage indicates that 
the mold is tight the wooden plugs are removed and all surplus 
fire clay blown out through a small blowout gate provided 
in the lower part of the mold. 

Preheating. — The rails are now ready for preheating, and 
must be brought to a bright-red heat. For this purpose a 
special portable heater is used. 

The opening in the mold through which the rails are lieated 




Fig. 59. — Mold and Crucible Clamped in Position Eeady for I'rehealing. 
Box Containing Additions Set in Eiser of Mold. 



is situated about two-thirds from the top, so that the flame 
strikes the lower portion of the web of the rail and has the 
effect of heating the entire rail section uniformly. This pre- 
heating also accomplishes two other objects, as it bakes the 
mold and at the same time heats up a can of additions Avhich 
are added to the Thermit in the crucible to improve the quality 
of the steel produced. This can of additions is placed on 
top of the mold in a special receptacle provided for the purpose 
in the riser opening, as sliown in Fig. 59. As soon as the 
rai^.s are red hot, the mold thoroughly dried, and the can of 



398 



GAS TORCH AND THERMIT WELDING 



additions heated to the proper temperature, the hurner is with- 
drawn and the heating gate plugged witli a sand core. The 
burner is then directed down tlie pouring gate in order to 
restore any heat that may have been lost during the plugging 
operation. 

The mold is now ready for pouring, and the crucible is 
placed in position, the reaction started and the melt tapped, 
just as described for other work of this character. 

The steel enters the mold on the lip side of the rail and 
thoroughly melts and amalgamates with the lip as well as with 




Section through Rail Joint 
O'fter Pouring 



Fig. 60.— Sectional View of Eail Weld. 



the web, base and one side of the head. No Thermit steel 
is allowed to touch the running surface of the rail, as the 
steel insert closes up the space between the rail ends except 
for a small opening of about |- in. from the outside of the 
head. The under part of the insert is thoroughly fused with 
the liquid steel and becomes a part of the fusion weld, as shown 
in Fig. 60. 

As explained previously, when the metal in the weld begins 
to cool it produces sufficient pressure on each side of the insert, 
due to contraction, to thoroughly butt weld it in position so 
that at the end of the operation the entire rail is welded into 



»• 



RAIL WELDING FOR ELECTRIC SYSTEMS 



399 



one homogeneous mass. A finished weld is shown in Fig. 61 
and in Fig. 62 is shown a number of operations going on 
at once. 

One of the principal advantages of this type of weld is 




Fig. 61. — Fiuisbed Tlicnnit Fully Welded insert Joiut. 

that it depends on a predetermined chemical reaction which 
is always uniform. The success of the reaction is assured by 
the fact that every Thermit-welding portion is weighed out 




Fig. (52. — Preheatiug Eails, Drying Molds and Heating Thermit Additions, 
All in One Operation, Four Joints Being Heated at Once. 

separately for each rail section to be welded and in just the 
proper quantity to obtain a perfect weld on that section. 

The placing of the additions in a sheet-iron container is a 
fairly recent improvement and has resulted in not only obtain- 
ing a higher grade of steel in the weld than was possible 



400 GAS TORCH AND THERMIT WELDING 

formerly but also permits of obtaining a greater quantity of 
steel from the Thermit used. This in turn permits a weld to 
be made with less Thermit than formerly and has considerably 
reduced the expense of the welded joints. 

THE USE OF ADDITIONS 

The scheme of employing the additions as outlined is to 
use plain Thermit, and instead of mixing the additions of 
manganese, nickel and other materials for improving the 
quality of the Thermit steel throughout the Thermit itself these 
additions are now put up in the sheet-iron container which 
is placed on top of the mold during the preheating and is heated 
red hot by the waste gases. It is then placed in the center 
of the crucible and is melted down by the heat of the Thermit 
reaction. 

This method enables the production of more steel from a 
given amount of Thermit without any sacrifice of heat, with 
the result that the cost of the welding portion of Thermit is 
considerably reduced. 

After the weld has been poured the mold should he left 
tmdisturhed for a few hours; in fact, the longer it is allowed 
to cool the better, as the metal in the weld lias time to become 
properly annealed. The mold boxes can then be removed, 
the metal left in the risers and pouring gates cut off by 
nicking Avith a hammer and chisel and knocking off. All sand, 
etc., is cleaned from the rail in the vicinity of the mold and 
the joint is ready for grinding. 

The Grinding- Machine. — As the steel insert is left a trifle 
higher than the rail section this excess metal must be ground 
off together Avith the excess metal left in the groove and on 
the outside of the head where the riser is removed. 

This grinding can best be accomplished by means of tlie 
machine shown in Fig. 63. It possesses the advantage that 
the weight is concentrated over the grinding Avheels so that 
a deeper cut can be taken. It also has attachments permitting 
of grinding in the groove of the rail and on the gage. If 
only a very few joints are being welded, however, the grinding 
can be very satisfactorily accomplislied with a flexible-shaft 
grinding machine. In fact one of the great advantages of 



RAIL WELDING FOR ELECTRIC SYSTEMS 



401 



the Thermit process of rail welding is that a few joints can 
be welded almost as economically as a large number, and trac- 
tion companies can do the work themselves wherever they 
please, and when the work is properly organized a gang of 
nine men can weld from 35 to 40 joints in a nine-hour day. 

The simple and portable character of the welding outfit, 
including the grinding machine, is a strong point of merit, 
as one service car will carry all the equipment or it can be 
hauled on its oAvn wheels. 




Fig. 63. — Rail-GriiuUng; Machine Derailed Under Its Own Power. 



The rail-grinding machine referred to was originally dc-- 
signed by the Thermit company for grinding Thermit-welded 
rail joints, but has proved very efficient for grinding out 
corrugations, pounded joints, and in fact anything that is 
required for a rail-grinding machine on an electric-railway 
system. An important feature is tlie derailing device which 
permits the removal of the machine from the path of traffic 
very quickly. The concentration of the weight over the grind- 
ing wheels has already been mentioned. By this arrangement 
deep or light cuts may be taken Avithout danger of the grind- 
ing wheels chattering. The truck frame carries two axles. 



402 GAS TORCH AND THERMIT WELDING 

One axle is fitted with ordinary 22-in. ear wheels and the 
other has eccentrically mounted 13-in. wheels. By means of 
sliding adjustments the wheels may be spaced on their axles 
to fit road gages of from 4 ft. 8^ in. to 5 ft. 2^ in. The grind- 
ing-wheel brackets have both vertical and horizontal movement 
to allow for adjustment to the work. The bracket also may 
be rotated so that the face of the grinding wheel may be 
adjusted to the surface to be ground. By a special arrange- 
ment of the motors used the machine can be driven forward 
at a rate of 2 or 4 ft. per minute and 6 to 12 ft. per minute on 
the return. A reversing switch permits speeds to be used 
in either direction. 

Where it is desired to grind out a depression a special 
arrangement is used by which an accurate curve is obtained. 
The grinding wheels run about 1833 r.p.m., which corresponds 
tc a peripheral speed of 6719 ft. per minute on a new 14-in. 
wheel. The grinding-wheel motors are rated at 3^ hp. and tlie 
propelling motor at If hp., and they are designed to operate 
on 500 to 550 volts. The derailing device operates by power 
and is quickly brought into use. The complete machine weighs 
about 6000 pounds. 



CHAPTER VII 
WELDING COMPROMISE RAIL JOINTS 

There is very often a demand for a compromise joint to 
be supplied quiclvly when some bolted or cast-welded joint 
has failed. An inexpensive shop-welding outfit enables traction 
companies to weld their own compromise joints in a few 
hours, and these will give the same results in service as a 
regular Thermit rail weld. 

When a large number of compromise joints are to be made 
on the same rail section it is advisable to have patterns and 
mold boxes made especially for the purpose. Where only 
tAvo or three are to be welded, however, the work can be done 
by the "wax method," which is the method used in all general 
repair work. To assist in the aligning and surfacing of the 
rails when two short lengths are to be welded together it is 
advisable to provide a suitable bed to which the rails can 
be bolted. Two stringers running about 10 in.X6 in.XJO ft. 
long, on Avhich four wooden or steel tics can be bolted, answer 
this purpose very well. The two center ties should be spaced 
about 18 in. in the clear and the second tie spaced to take 
care of the shortest length of rail to be welded. It is best to 
imbed the surfacing bed in the ground up to the top of the 
stringer. To hold the rails to the ties long bolts can be used 
in place of track spikes. These bolts should be allowed to 
project through the face of the tie a sufficient amount to take 
the smaller of the two rails. Allowance must also be made 
for a U-elamp, or bridge clip, one end of which will bear on 
the base of the rail and the other on the tie, or in the case 
of a small rail, will rest on a spacing block. 

To bring the smaller rail up to the surface of the high rail 
a filling block is placed under the base, and to obtain accurate 
surfacing, shims or old hack-saw blades may be used in addi- 
tion. With the rails spaced | in. apart and accurately adjusted, 

403 



404 GAS TORCH AND THERMIT WELDING 

the U-elamps are bolted down tight and the insert fitted as 
described for making ordinary rail welds. If patterns and 
mold boxes have been provided in advance the work proceeds 
in the same way as for ordinary rail welding, bnt if the wax 
method is to be used about 3 lb. of wax should be broken 
into small pieces, placed in a pan and heated until entirely 
melted. The wax is then allowed to cool until it becomes 
plastic. It may then be shaped by hand around the rail ends 
in the form of a collar. 

USING A RAIL SECTION FOR A PATTERN 

In cases where five or six compromise joints are to be 
welded between the same rail sections considerable time and 
trouble can be saved by using a short length of each rail 
section as a pattern. These should be about 8 in. long, butted 
together and fastened by tacking with the oxy-acetylene-weld- 
ing process so that they will be held together securely. Mold 
boxes of sheet iron in two halves can be cut to fit with the 
oxy-acetylene cutting flame so that they will fit the sections 
to approximately ^/jc in. all around. Each half of the mold 
box will then have a different section cut in each side. A 
wax collar is formed around the joint of the two pieces of 
rail in the regular way as described above and the one-half 
oi tlie mold box is laid on the ground back down, placing the 
pattern made by tacking the two rail sections together on this 
half of the mold box. Then thin pieces of sheet iron are laid 
on top of this half to obtain a parting when the other half 
of the mold box is placed on top. The other half may then 
be placed in position and rammed up to the height of the 
riser with molding material, using a wooden pattern for the 
riser opening. "When this has been completed the whole mold 
box, pattern and all, is turned over and the bottom half of 
tlie mold l)ox rammed, inserting a wooden riser pattern in 
a similar way to the first half. This ])ottom half is then rapped 
slightly and lifted from the pattern. Then by rapping the 
pattern it may be lifted from the other half of the mold box. 
After removing the riser pattern the molds are ready to be 
placed on the rails to be welded, but before doing so the space 
between the lip and the ball of those rail sections should be 



WELDING COMPROMISE RAIL JOINTS 



405 



rammed flusli with molding material, "When the boxes are 
adjusted they should be luted carefully with fireclay around 
the outside edges between the mold and the rail to guard 




Fig. 64. — Welded Compromise Joint Between T-Eail and Grooved Eail. 




Fig. Gu. — Welded Compromise Joint Between Two T-Eails, Showing 

False Lip. 

against any run out of Thermit steel. The joint can then be 
preheated and poured in tlie regular way. 

This method will be found to save considerable time over 
waxing each joint separately, and the two short-rail sections 



406 



GAS TORCH AND THERMIT WELDING 



can be used as a pattern for any number of molds. If both 
right-hand and left-hand compromise joints are required the 
same pattern and mold boxes can be used by simply discon- 
necting and rearranging for either right or left. A welded 
compromise joint between a grooved and a T-rail is shown in 
Fig. 64. 

Where a compromise joint is to be welded between two 
T-rails as shown in Fig. 65 the same method can be used except 
that in this case it is necessary to arrange for a false lip to 
be cast out of Thermit steel similar to tlie lip of a grooved 
rail. In other words the Thermit-steel collar must be carried 
around each side of the head and on one side must be shaped 
in a corresponding manner to the lip of a groove rail. This 
is necessary because when the metal begins to cool and con- 
tract there must be an equal shrinkage force on each side of 
the insert extending to the top of the head tending to draw 
the rails together, otlierwise the insert will not be thoroughly 
butt-welded into the head. 

THE CLARK JOINT 

Shortly after the development of the Thermit rail-welding 
process; Charles H. Clark, chief engineer of the Cleveland 




Fig. 66. — Complotod Clark Joint. 

Railway Co., perfected a joint known as the ^' Clark joint," 

which has proved exceedingly successful in Cleveland and other 

Eastern cities where many thousand joints have been installed. 

In its original form it consisted of a combination of splice 



WELDING COMPROMISE RAIL JOINTS 



407 



bars and Thermit steel, it being Mv. Clark's opinion that the 
head of the rail conld be supported by using plates that would 




Fig. 67 —Open Mold aud Crucible in Position for Making Clark Joint. 




Fig. 68. — Completed Modified Clark Joint, Showing Weld of Base. 



come under the ball of the rail. Furthermore, in order to 
hold the rail rigid he considered it important that there should 



408 GAS TORCH AND THERMIT WELDING 

be no play in the bolts, so the holes in the plates and rails 
were drilled round and machine bolts used after reaming for 
a drive fit. In order to keep the bolts and plates from working- 
loose and to afford bonding between the rails a Thermit-steel 
shoe was cast around the base as shown in Fig. 66. 

In practice the rails and splice bars are drilled with holes 
Vi6 ill. less in diameter than the bolt to be used. The splice 



Fig. 69. — Section through Modified Clark Joint. It will be ISTotiecd that- 
the Lower Part of the Kail and Fish Plates are entirely Amalgamated. 

bar is then applied in the ordinary way and held in place by 
a couple of temporary bolts, a drift pin being driven into one 
hole each side of the joint to keep the rails in position. The 
remaining holes are then reamed with straight-end cutting 
reamers, after which the machined bolts are driven and tight- 
ened up in the usual manner. After preheating the rail ends 
the Thermit steel is run into an open mold surrounding the 
lower part of the rails as illustrated in Fig. 67. 



WELDING COMPROMISE RAIL JOINTS 



409 



In tlio latest type of Clark joint rivets arc substituted for 
the machined bolts, the riveting being accomplisbed by a 
pneumatic riveter suspended from the rear end of a flat car 
carrying an air compressor. 

A modification of the Clark joint, shown in Fig. 68, has 
been adopted with marked success by the United Railways and 
Electric Co., Baltimore, and is also being used on other 
properties. 

The object of the modification was to obtain a larger weld 




Fig. 70. — Appliances in Position for Welding Third Rail. 

of the base, and in order to do this the Thermit steel was 
poured into an inclosed mold box instead of into an open mold 
and the rail ends were preheated to a red heat with the molds 
in place before the Thermit charge was ignited. Furthermore, 
the design of the fish plates is somewhat changed, these being 
of special design 1 in. in thickness and 32 in. long and being 
so formed as to fit snugly the contour of the head and base 
of the rail. At the same time they provide a minimum amount 
of space betAveen the web of the rail and the vertical sides 



410 



GAS TORCH AND THERMIT WELDING 



of tlie fish plates. The eliannel bars and rails are of the same 
kind of steel (liigh carbon) and both are punched at the mill 
with ten IVic-ii^- holes, spaced 3 in. centers and beginning 
2 in. from the end of tlie rail. 




Fig. 71. — A Welded-Up Cross-Over. 




Fig. 72. — Motor Case with Broken Lug Previous to Welding. 



The joint has been applied thus far exclusively for 7-in. 
girder groove rails weighing 103 lb. per yard. These 7-in. 
girder sections are undercut by the manufacturers ^/jg in. so 
as to provide a space of ^ in. at the base when the rail heads 
are butted. This jprocedure more effectively enables the 



WELDING COMPROMISE RAIL JOINTS 



411 



Thermit steel to weld the rail and fish plates into a solid mass 
at the joints, as shown in the section, Fig. 69. 

Welding- the Third, or Conductor, Rail. — The welding of 
the third rail has been carried on more extensively abroad than 
in the United States. This is especially true of France, where 
several thousand joints have been welded for the Metropolitan 
Eailway and others in the neighborhood of Paris where this 
method of bonding is now standard practice. 

In making these welds in France the base and flange only 
of the rail was welded Avith Thermit steel. 

As a great deal of third rail, both here and abroad, is used 




Fig. 73. — Motor Case Welded and Eeady for Service. 



in tunnels and subways, it is not necessary to make any provi- 
sion in such cases for expansion and contraction, it having 
been found from practical experience that the temperature 
changes seldom exceed 25 or 26 deg. F. These are the figures 
that were determined by experiment in the subways controlled 
by the Metropolitan Eaihvay of Paris. In cases, however, 
where the third rail is laid in open stretches of track where 
it will come under tlie full influence of atmospheric changes 
in temperature it is of course necessary to provide suitable 
means for taking care of the expansion and contraction, and 
this can be easily done by installing an expansion joint at 
regular intervals. 

Welding third rails has advantages that need hardly be 



412 GAS TORCH AND THERMIT WELDING 

enlarged upon, providing, as it does, for a nniform electrical 
conductivity of the rail in question and a method of bonding 
which will not deteriorate. 

A Thermit outfit in position for welding a tlurd rail is 
shown in Fig. 70. 

A very simple way to make cross-overs of any desired form 
is shoAvn in Fig. 71. Tlie rails are cut, shaped and then 
Thermit welded together and then the surfaces are ground. 




Tig. 74. — Weld on Broken Tinek Frame. 

The result is as smooth and solid a cross-over as it is possible 
to make. This is suggestive of many other similar uses. 

The same outfit required for welding compromise joints 
can be used most advantageously for welding motor cases and 
truck frames. The process offers special advantages for such 
repairs, OAving to the fact that the collar, or reinforcement of 
Thermit steel, which is fused around the weld may be made 
heavy enough to insure against future breakage. 

In Fig. 72 is shoAvn a broken motor case, and in Fig. 73 a 
welded one. A welded truck frame is shown in Fig. 74. 



CHAPTER VIII 
WELDING CAST IRON AND OTHER PARTS 

The Tliormit process, while adapted to the weldmg of cast 
iron, cannot be nsed on all cast-iron welds owing to the diffi- 
culty in many cases of allowing properly for the shrinkage 
of the metal in the weld when cooling. The Thermit steel 
contracts twice as much as the cast iron, so that in certain 
constructions shrinkage strains will be set up in the weld 
causing cracks. Tliis difference in shrinkage often makes it 
impractical to weld long cracks in thin sections. As a general 
rule we should say that if the length of crack is more than 
eight times the thickness of the material a Thermit weld should 
not be attempted, because on account of the difference in 
shrinkage along the line of the fracture small hair-line cracks 
will appear perpendicular to the line of the fracture. These 
cracks, however, being perpendicular to the line of the weld 
are often therefore of little consequence and do not interfere 
with the strength of the weld. 

It is also not usually feasible to weld cracks in cast-iron 
cylinders, pots, kettles and similar castings. Where there is 
a clean break between two sections or where the section to 
be welded can be completely cut through and can be separated 
a sufficient amount to allow for the contraction in the weld, 
and also where the length of the weld is not more than eight 
times the thickness of the material, a Thermit weld would 
be entirely practical and can be made in exactly the same way 
as outlined for the welding of wrought-iron and steel sections. 

In cases where the crack can be opened up mechanically 
or by lieating a parallel part to a dull red a weld may be 
made, but it must be remembered that expansion gained in 
this way must be a little more than the expansion of the parts 
next to the weld during the preheating. 

Care should be taken in preheating for cast-iron welds not 

413 



414 GAS TORCH AND THERMIT WELDING 

to heat tlie sections too hot ; a dull red is sufficient. One 
should be careful to keep the heat going until the mold is 
thoroughly dried out. 

The mixture of Thermit for the weld should he different 
than for wrought iron and steel, and for this purpose the 
special mixture known as cast-iron Thermit is recommended. 
This consists of plain Thermit with which is mixed 3 per cent 
ferrosilicon and 20 per cent mild-steel punchings, i.e., to 
every 100 lb. of plain Thermit is added 3 lb. of ferrosilicon 
and 20 lb. of punchings. This gives the best results on cast 
iron and produces a homogeneous metal in the Avelcl. 

Welds on cast iron are a little more difficult to machine 
than welds on wrought iron and steel, as the metal along the 
line of junction of the Ther-mit metal and the cast iron is apt 
to be a ti'ifle hard due to the absorption of carbon from the 
cast iron. This objection is not a serious one, however, and 
hundreds of welds have been completed with the most satis- 
factory results. 

Examples of Cast-iron Welds. — In order to show the pos- 
sibilities of welding various cast-iron pieces with Thermit a 
few examples taken from actual practice are given. 

Fig. 75 shows how a new jaw was burned onto the frame 
of a heavy shear, in the shops of the Kaleigh Iron Works Co., 
Raleigh, N. C. The job was done in 1906 and the machine 
is still in service. This machine was designed for shearing 
l-|X6-in. bars, producing an enormous strain on the jaw^s. 
A large part of the corner of the lower jaw, weighing about 
75 lb., broke off. It then became a question of getting a new 
frame or burning on a new jaw corner, which would require 
the fusing of a surface about 1 sq. ft. in area in order to obtain 
a thorough union. It was finally decided to try Thermit. The 
surface of the break was chiseled off for the reason that a 
cast-iron break is usually glazed with graphitic carbon. The 
mold was then put in place and well luted with fire clay where 
there was any danger of leakage. Moist sand was also rammed 
around the mold and other parts as a further precaution. The 
surface of the fracture and the stock around the jaw was then 
heated through the gates and risers by means of gas jets, 
in order that the casting might be thoroughly heated and all 
moisture driven out. The gas torches were kept in action 



WELDING CAST IRON AND OTHER FARTS 



415 



several houi's. A crucible containing 175 lb. of Thermit Avas 
then put ill position for tapping into the mold. After the 
reaction tlie Tliermit steel was run into the mold and at once 
fused the entire surface of the fracture. In the meantime a 




Fiu. 75. — New Jaw Burned to Frame Castiiis^ of Heavy iShear. 



ladle of molten cast iron containing about 600 lb. of metal was 
held in readiness and was superheated by means of a Thermit 
semi-steel can. As soon as possible after pouring the Thermit, 
this cast iron was poured into the second gate, shown at the 
front of the jaw, and this forced the Thermit steel out of the 



416 GAS TORCH AND THERMIT WELDING 

mold after it had served its purpose in bringing the surface 
of the jaw to a Avelding or fusing heat. The result was a 
new corner of cast iron burned onto the old jaw. The illus- 
tration shows the two gates and four risers before they were 
trimmed off. In Reactions for the fourth quarter of 1917 
W. J. Musick, blacksmitli foreman of the St. Louis shops of 
the Missouri Pacific R.R. wrote : 

We recently had one of our ste;un liannners break tlirouLcli both 
sides of the frame and through the throat, the fracture Ix'in.i; Gl in. 
long. This hammer was so badly broken that it seemed as thou-h 
it were doomed for the scrap pile. 

A new . team hammer was ordered, but in the meantime it was 
decided to try to repair the old one with Thermit. The weld was 
made and a successful repair was accomplished, resulting in saving 
a considerable amount of money. 

^^'e have also Avelded a cast-iron engine bed for the Helmbacher 
Rolling Mill Co. The !)cd of this engine is 32 in. high and 12 in. across 
the top. The mill was only shut down 24 hours while the repair 
was being made. 

Master Mechanic George M. Stone, writing in the same 
, publication, says : 

I think your readers will be interested in the accompanying illus- 
trations of Thermit welds which have been made by me in the shops 
of the Chicago, Rock Island and Pacific Railroad, Chickasha, Okla., 
and I would like to call particular attention to the welding of valve 
seats on locomotive cylinders, which I consider an exceptionally good 
piec<? of work in view of the fact that these are cast-iron cylinders. 
The manner in which we handled the work was as follows : 

The ports of the cylinders were cracked through from the steam 
port to the exhaust port. A Thermit Aveld was made on these cylinders, 
and in order to do this the entire cylinder was cut loose from the 
frame and smoke arch of the locomotive. The pistons were removed 
from the cylinders, as well as the cylinder heads both front and back. 
The cylinder was then preheated with a slow wood fire and welded 
with Thermit. 

We have also had very good success with the welding of spokes 
in driving-wheel centers and the welding of main frames on one of 
our heaviest classes of engines in freight service. 

These instances show that in many cases the success or 
failure of a cast-iron welding job is merely a matter of good 
judgment. As in other kinds of welds, expansion and con- 
traction must be allowed for, and in many cases where a purely 



WELDING CAST IRON AND OTHER PARTS 



417 



TluTiiiit wt'Ul wt)uld be out of the question, owing to the 
difference in eontraetion of cast iron and Thermit steel, the 
Thermit may l)e used merely to bring the broken surface up 
to a fusing lieat and then molten cast iron may be burned 
on. as was done with the shear jaw previously mentioned. 

The illustrations here given show how Thermit welding 
may be applied to various cast-iron machine parts. Fig. 76 




Fig. 76. — Weld on 4S-In., 6S 000-Lb., Cast Iron Blooming-Mill Housing. 
About 3500-Lb. of Eailroad Thermit Used. 



shows a weld on a 48-in. blooming mill housing, wdiieli weighed 
68.000 lb. Approximately 3500 lb. of railroad Thermit was 
used. Fig. 77 shows a weld on a rolling-mill bed made for 
the AYaclark Wire Co., Elizabeth, N. J. The iveld shown in 
Fig. 78 was on a 25-ton nail-machine housing, and 650 lb. of 
Thermit was used. Another housing weld on a knuckle machine 
made by tlie Standard Parts Co., Cleveland, is shown in Fig. 



418 



GAS TORCH AND THERMIT WELDING 



79. Many times breaks on machine-tool parts could be repaired 
in the same way. 

Welding- High-Speed Steel to Machinery Steel. — The largest 
weld ever made, np to Jannary, 1919, was a cast-iron weld 
on a blooming-mill shear at the plant of the Pittsburgh Steel 




Fig. 77. — Cast-iron Eolling Mill Base Repaired for the Waclark Wire Co,, 

Elizabeth, N. J. 




Tig. 78. — Repair on a 25-Ton Nail-Machine Housing. 

Co. The broken piece was of irregular shape approximately 
37 in. wide by 5 ft. 6 in. long and weighed about 3000 lb. 
Five No. 10 crucibles were used for the job. 

Sometimes it is advisable to weld tool or high-speed steel 
to a mild-steel bar or shank. Tliis is perfectly feasible for 
special drills, reamers, boring bars or special tools of various 



WELDING CAST IRON AND OTHER PARTS 



419 



kinds. Where only one or two jobs are to be done ordinary- 
welding by the wax-core method may be employed, but where 
many pieces are to be welded it will pay to make molds. A 




Fig. 79. — Cast-iron Housing of Knuckle Mai'lune, Welded by the Standard 
Parts Co., Cleveland, Ohio. 




Fig. so. — Machinery Steel and High-Speed Steel Eeady to Clamp Mold. 

mold for welding round bars together is shown in Fig. 80. 
The pattern and mold box for this are shown in Fig. 81. 

High-speed steel blades may also be welded into large or 



420 



GAS TORCH AND THERMIT WELDING 



emergency job reamers in a comparatively short time. For 
this purpose a cylinder is bored out slightly larger than the 
liole to be reamed. The blades for the reamer are placed inside 
this cylinder and wedged into their proper places. Tin or 
wooden spacing pieces may be used for this if they are so 
placed as to be removed after the wax hardens. After the 
blades are fixed in position another cylinder or piece of pipe 
is centered inside the blades, alloAving space between the blades 
and this cylinder according to the size of the reamer being 
made. Wax is next poured into the spaces between the blades 



> liHi^PW 


L 


1 1 --^ 




i 




'f ' 


^ 


l^i^iMii 


HHHi 


1 "*! 








, 




i; 


1 , 
t 

1 




i 1 
1 




li 






1 




^ 











Fig. 81. — Sheet-Iron Mold Box and Wooden Pattern. 



and the inner cylinder. After it is removed from the outer 
cylinder and the wax hardens, enough of it is trimmed away 
between the blades to allow for chip space. The wax matrix 
with the blades in place is then rammed up in a mold. The 
inner cylinder is then warmed slightly and removed. A steel 
shank is next inserted and centered correctly. The wax is 
now melted out and the Tliermit steel run in, welding the 
blades securely to the steel shank. A wax matrix, with blades 
and inner cylinder in place, is shown in Fig. 82. In this 
illustration the wax has been cut away between the blades 
and the assembly is ready to be put into the mold box and 



WELDING CAST IRON AND OTHER PARTS 



421 



be rammed up. When the work is cool it is centered and 
the blades ground for size and clearance. 

A helical reamer with inserted high-speed steel blades is 
shown in Fig. 83. This reamer was made by T. 0. Martin, 




Fig. 82.— High-Speed Steel Cutters Held in Wax Pattern with Hollow 

Steel Core 




Fig. S3. — Helical Inserted-Blade Reamer Made by the Thermit Process. 

blacksmith foreman of the Illinois Central R.R. shops at Jack- 
son, Tenn. 

Preheaters for Thermit Work. — As practically all welds 
in ordinary practice, except those on pipe, require preheating 



422 GAS TORCH AND THERMIT WELDING 

it is well to use heaters made for the purpose wherever possible. 
In some shops gas- burning torches supplied with compressed 
air may be used. Many shops, however, have neither gas 
torches nor compressed air. This method is not practicable 
on outdoor welds. Crude-oil heaters should not be used at 
all, on account of their tendency to deposit carbon or other 
matter on the surfaces to be welded, thereby causing imperfect 
welds. In order to make the preheating work as easy and 
convenient as possible the Metal and Thermit Corporation 
makes the preheaters here shown. Fig. 84 shows two kinds, 
a single and a double burner. For infrequent or small jobs 
the single burner, which may be fitted with a flaming burner 
also, will probably answer the purpose. Where a number of 

Table V. — Cost of Thekmit and Apparatus fofv General Welding 

Gross Lb. 
Shipping Weiglit Cost 

Railroad Thermit (.50-lb. boxes only ) 67^ $17.50 

I'lain Thermit (50-lb. boxes only) . ,59 17.00 

Cast-iron Thermit (.50-lb. boxes or.ly ) 70^ 17.50 

Ignition powder (i-lb. cans) .45 

Yellow wax, per pound . . . .35 

Punchings, per pound .025 

Special molding material (300 lb. ) 340 4.00 

Fire clay (300 lb. net) 340 8.50 

Fire brick, per barrel (300 lb. net ) 340 4.00 

Kiln-dried silica sand (.300 lb. not ) 340 3.50 

Single-burner preheater 200 50.00 

Double-burner preheater 225 75.00 

Flaming-burner attachment 3.00 

Magnesia stones, No. 1 .15 

Magnesia stones. No. 3 .20 

Magnesia thimbles, No. 1 .10 

Magnesia thimbles, No. 3 .15 

Magnesia tar, about 400 lb. net 450 .06 

I*lugging< material, No. 2 package .10 

Automatic crucibles (with ca:is and rir.gs) 40 4.00 

Automatic crucible, No. 2 60 5.50 

Automatic crucible, No. 5 1,50 11.00 

Automatic crucible, No. 10 775 60.00 

Cast-iron relining cone, No. 1 50 5.00 

Cast-iron relining cone, No. 5 1.50 12.00 

Cast-iron relining cone, No. 10 600 40.00 

Tripods, Nos. 1 to 7, weights 11 to 05 lb .$2.50 to 9.00 



WELDING CAST IRON AND OTHER PARTS 423 




Fig. 84. — tSingle-Bunier and Double-Burner Preheaters, Using Either 
Gasoline or Kerosene. 




Fig. 85 —Rail Prelieater That Will Heat Four Joints at Once. 



424 



GAS TORCH AND THERMIT WELDING 



welds are to be made, however, tlie double-burner apparatus 
should be selected. In these illustrations A is the place to 
attach the hose from the compressed-air supply ; B is the valve 
for regulating the pressure on the surface of the fuel; C is a 
tube which runs within a few inches of the bottom of the 
tank; D is the needle valve which controls the fuel to the 
burner; E is the air pressure control to the burner; i^ is a 
check valve which prevents back fire ; G are torches or burner 
pipes ; // is a flaming burner. The small tank on the left side 
is a water separator for the compressed-air supply. 

Table VI. — Cost or Materials and Appliances for Pipe Welding 
Standard Weight Pipe. 





PRICE OF WELDING POBTION9 


Price 

of 
Mold 


















Inside 
Diam- 
eter, 
loches 


100 

Less 


Over 
100 and 
Le33 
than 
500 


Over 
SCO and 
Less 
than 
1000 


1000 
More 


Price and 

Size of 
Crucibles 


Price and 
Size of 
Tongs 


Price and 
Size of 
Clamps 


Price and Size of 
Pipe Facing 
Machines 


H 


$0.36 


$0.32 


$0.27 


$0 19 


$0.75 


No. 2] 




No. 2 




No. 1] 




No. 11 




H 


.44 


.40 


.36 


.26 


.75 


2 




2 












1 


-CO 
.78 
.90 


.56 
.74 

.86 


.55 
.69 

.84 


.39 
.60 
.75 


1.00 
1.25 
1.50 


2 
2 
2 


$1.75 


2 
2 
2 


$2.00 




$20 00 




$35.00 


2 


1.03 


.99 


.97 


.90 


1.75 


2 




2 












2H 
3 


1.50 
2.16 


1.46 
2,12 


1.43 
2.09 


1.35 
2.06 


2.00 
2.25 


31 
3i 


3.00 


3 
3 


2.50 










3H 
4 


3.06 
4.63 


3.02 
4.59 


2.99 
4.56 


2.96 
4.50 


2.50 
2.75 


41 
4J 


^ 4.75 


4 

4 


3.25 


2 

2J 


> 25.00' 


2 

2i 


60.00 



EXTRA HEAVY PIPE 



U 
1 

IK 
VA 

2 

2H 
3 

3H 
4 



$0.45 


$0.42 


SO. 37 


$0.29 


$0.75 


.54 


.43 


.42 


.34 


,75 


.72 


.67 


.62 


.56 


1,00 


.90 


.86 


.84 


.75 


1,25 


1.14 


1.10 


1.05 


.98 


1.50 


1.78 


1 75 


1.71 


1,65 


1,75 


2.94 


2.90 


2.86 


2.80 


2.00 


4.23 


4.20 


4.16 


4.10 


2,25 


5.43 


5.40 


5.36 


5.10 


2,50 


6.22 


6.18 


6.14 


6.08 


2,75 



1.75 



3.00 
4 75 



5 7,50 



21 

2 

2i$2,00 

2 

2J 

3 

4: 



2.50 
3,25 



5 4 50 



$20.00 



25.00 



$35 00 



60.00 











DOUBIiE EXTRA HEAVY PIPE 










Vi 


$0,93 


$0.90 


$0.86 


$0.81 


$1.50 


No-2|$1.75 


No. 2] 


No. 1 




No. 1 




H 


1.08 


1.04 


1.02 


96 


1.75 


2 $2.00 










1 


1.20 


1.16 


1.14 


1.08 


2.00 


l\ 3-00 l\ 

4 3} 2.50 










VA 


1.49 
2.14 


1.43 
2.08 


1.41 
2.03 


1.36 
1.94 


2.25 
2.50 




$20.00 




$35 00 


2 


3.82 


3.73 


3.71 


3.68 


2.75 










2H 


7.30 


7.27 


7.24 


7.20 


3.00 


1} 7-50 


1} 4-50 










3 


10.60 


10.57 


10.54 


10.50 


3.50 


' 









Fig. 85 shows a four-burner portable apparatus used largely 
for rail-welding work. It carries its own air compressor, 



WELDING CAST IRON AND OTHER PARTS 425 

which may be run by attachmg to a trolley wire or to some 
other olectric-ciirrent supply. All of these burners use either 
gasoline or kerosene. 

Cost of Thermit Welds and Apparatus. — There are many 
factors winch enter into the calculation of the cost of Thermit 
welding and the apparatus. Where a single weld is to be 
made and the shop man has to buy the apparatus, materials 
and do the work himself, the cost will naturally be higher 
than where several welds are to be made or where he can 
hire it done. There are so many places now making a specialty 
of Thermit welding that in ordinary circumstances it is usually 
better to have them do the work on large jobs than for inex- 
perienced men to undertake the work. 

Data for the appropriate cost of various jobs have been 
given in tables and specifications throughout the article, but 
in order to give those responsible for repair or other welding 
work, as exact information as possible on which to base their 
calculations, the accompanying tables are included. These 
are taken from the price list of the Metal and Thermit Cor- 
poration, published June 15, 1918, and of course are subject 
to changes. These quotations are f.o.b. Jersey City, N. J. 
Table V gives prices for general welding materials, and Table 
VI for pipe work. It will be noted that some of the quotations 
in this last table do not exactly agree with figures given in 
the table of comparative costs of Thermit welded and 
mechanically-joined pipe, but it should be borne in mind that 
the comparative table gives averages only, and is also subject 
to variations in cost of labor and materials. 



INDEX 



A 

Acetone, 26 

— , capacity of, for acetylene, 27 

— injurious to weld, 28 
— , nature of, 26, 27 

Acetylene and Welding Journal, 144 
— , cubic feet per pound, 28 

— cylinder filling material, 27 
, capacity of, 27 

— , danger point of, 26 
— , discovery of, 1 

— , estimating amount of, in cylin- 
der, 28 
— , explosive limits of, 6 

— gas from pound of carbide, 29 

— generator, Davis-Bournonville 

"Navy type," 32 
— , heat units in, 3 
— , ignition temperature of, 6 

— manifolds, *118 

, Davis positive-pressure, de- 
scription of mechanism, 32 
, positive-pressure, *30 

— — , details of 300 lb. size of, *31 
, low-pressure type, phantom 

view, *42 
, Oxweld portable pressure 

tjTpe, 36, *39 

repairs, 45 

sets, dimensions and weights 

of, 37 

— generators, capacity of, 29 

, low pressure, 41, *42, *43 

, Navy type, size of, 35 

, positive-pressure, capacity, 29 

, pressure limit of, 30 

, standard rating, 29 

, the three types of, 28 

■ , -types, 28, 29 



Acetylene plant layout, *34 
, "Navy type," *33 

— positive-pressure generator, 29 
— ■ pressure generator, first, 2 

— , production of, 26 
— , specific gravity of, 6 
Action of cutting torch, 257 
Adaptors for regulator and cylinder 

connections, *103 
Additions, use of Thermit, 400 
Air chisel for welding work, *187 
— - Reduction Sales Co., 92 

— screen for cooling, 201, *202 
Airco-Vulcan combination welding 

and cutting torch, *91 
Alexander Milburn Co., 92 
All-steel welding truck, *35 
Allowance for expansion and con- 
traction, 154 
Aluminum gear case, repair of, 205, 
*207 

— oxide, melting point of, 174 
— , preheating, 175 

—, purity of, 173, 174 

— sodium fluoride, 174 
— , welding, 173 
fluxes, 174 

American Blaugas Corporation, 5 

— Machinist, 208, 215, 231, 236, 

244, 247 

— Society for Testing Materials, 

rail specifications of, 391 

— Welding Society, 267 
Amount of Thermit to use, 345 

— ■ — ■ — used in roll welding, 379 

Anchor welds, *385, *386 

Angle iron used in welding, *225, 

*226 
Apparatus, cost of Thermit, 425 



427 



428 



INDEX 



Applications of Thermit fusion weld- 
ing, 338 

Areas of drill holes, 65 

Armour Institute of Technology, 51 

Asbestos and molasses strips, use ot, 
395, *396 

Assembly for welding and cutting, 
*105, *109, *111, *117, *12G, *127, 
*128 

Automatic crucible for Thermit, *333 

Automobile cylinder, broken, *189 

— — welding, 164, *165 
"Autogenous Welding," 1 
Autogenous Welding, 272 

B 

Back-pressure valves, *124, 125 

Backward welding, 144, *147, *148, 
*149 

Baking Thermit crucible, 335 

Barium peroxide for igniting Ther- 
mit, 326 

Bastian-Blessing Co., 64, 90 

Battery, storage, burning, 152, 15;! 

Benzine vapor, 5 

Benzol vapor, 5 

Bethlehem Shipbuilding Corp. 
Acetylene plant, *33 

Beveling boiler flanges, *289 

Bisulphates of sodium and potas- 
sium, 174 

Blaugas, discovery of, 5 

— , explosive limits of, 6 

— , — range of, 5 

— , makers of, 5 

■ — ; method of selling, 5 

Blau, Herman, 5 

Blooming-mill housing Thermit weld, 
*417 

Blowing a hole_ through a plate, *261 

Boiling point of liquid oxygen, 10 

— nitrogen, 10 

Bond, rail, *204, *205 

— welding outfit, *205 
Bosses, forming, *143 
Bournonville, Eugene, 2 
Brass and bronze welding, 176 
Brennan, A. F., 216 



Bronze and brass welding, 176 
Buckeye carbide feeding mechan- 
ism, 36, *38 

— oxygen generator, *11 

— ■ portable oxygen generator, *12 
Building up a weld, *141 
Burning battery cell connectois, 153 
— , lead, data on, 153 

— out carbon, 302 
Butt joints, lead, 151 

— -welding plates, *134 



Calcium carbide, 2, 26 

— — , how handled, 26 
Calculating amount of Thermit, 346 

welding gases, 63, 64 

Calmbach, G. M., 200 

Camograph cutting machine, *286, 

*287 
Capacity of Oxweld generators, 40 

oxygen cylinders, 9 

Carbide, amount of acetylene pro- 
duced, 29 

— feed, Buckeye, 36, *38 
— , size of, 29 
Carbo-Hydrogen Co., 87, 262 

— cutting torches, 87, *88, *89 
Carbon burning, 302 

outfit, *304 

— • electrode and oxygen jet torch, 
*274 

— monoxide, 2 

Card for cost keeping, *301, *303 

Carhart, H. A., 231 

Carnegie Steel Co., 208 

Carrying case for cutting or weld- 
ing outfits, *120, *122 

Cartridge, Thermalene, 46, 47, *48, 
50 

Cast, aluminum, purity of, 173, 174 

— iron, cutting, 267 

, samples of cut, *272 

Thermit, composition of, 321 

to steel, welding, 179 

welding, 177, 178 

, with Thermit, 413, *415, 

*4]7, *418, *419 



INDEX 



429 



Chain links, building up, 205, *207 
Chapman, R. E., 274 
Characteristics of welding flames, 

*107, *113, *114 
Charging an acetylene generator, 

44 
Chemical oxygen generator, *11 

— symbol lor acetylene, 1 

calcium carbide, 2 

Chemistry of the oxy-acetylene 

flame, *107, 110 
Chlorate of potash oxygen genera- 
tors, size of, 12 

process, amount of oxygen 

produced, 10 

for oxygen, 10 

Chlorides of sodium, potassium, 

lithium, 174 
Chrome steel welding, 186 
Circular cutting, 284 
City gas, ignition temperature of, 6 
Clark, Charles H., 406 

— joint, the, *406 

, the modified, *407, *408, 409 

Cleveland Eailway Co., Thermit 

welded joints for, 406 
Coal gas, explosive limits of, 6 

, specific gravity of, 6 

Collars, building up, *143 
Colors of tank and hose, 101 
Combination torches for cutting and 
welding, *91, 92 

— welding and cutting torch, Mil- 

burn, *91, 92 
Commercial Gas Co., 274 
Compromise rail joints, welding, 

403, *405 
Conductivity and oxidation, 169 
Connecting up and lighting the 

torch, 104, *105, 109 
Containers for poison-gas, welding, 

*230, *232 
Contraction and expansion, 154 
Cooling devices, 201, *202 

— oven, Wiederwax, *161 

— work, 160 

Conveyor roller welding, *227, *228, 
229 



Copper, flux for, 180 

— to steel, welding, 180 

— welding, 179 

Corsair, welded anchor of, *386, 389 
Corunna, sterupost weld on, *389 
Cost keeping form, *301, *303 
— , — track of, 302 

— of cutting, 266, 267 

oxy-hydrogen cutting, 276, 276 

Thermit apparatus, 422 

pipe welds, 329, 330, 424 

welds, 424, 425 

welding large cylinders, 211 

per foot, 204 

Cracks, how to locate, 364 
Crank case, broken and repaired,. 
*191 

welding, *225, *226 

Crankshaft welding jig for Thermit 
work, *361 

— repair, 192, *193 

— welding, *223, *224, 225 
Crankshafts, welding with Thermit, 

359, *363, *364 

Crane, portable, for welding shop, 
*299 

— , trolley, and hoist, *296 

C, E. I. & P. R. R. shop work, 
416 

Crosshead welding with Thermit, 351 

Cross-over rails welded with Ther- 
mit, *410 

Crucible, baking Thermit, 335 

— holder for locomotive work, *355 
— , lining Thermit, *333, 334 

— , Thermit automatic, *333 
— , tapping Thermit, *334 
Crucibles, details of Thermit, *333, 

337 
Crude oil or kerosene preheater, 

*157 
Cumming, J. R., 202 
Current required for separatiHfT oxv 

gen and hydrogen, 16, 20 
Cut, size of, made by a cutting 

torch, 75 
Cutting a rivet head, *261 

— action of a gas torch, 74, 75 



430 



INDEX 



Cutting and welding outfits, 116, 
*117, 119, *120, *122, *126, 
-n27, *128, *129 

— cast iron, 267 

—, circular, 284, 285, 288, 289, 292 
— , cost of, 266, 267 

— data, 85 

— , learning how to do, *258, *259, 
*260 

— machines, *278, *279, *280, -281, 

*282, *283, *284, *285, *286, 
*287, *288, *289, *290, 291, 
*292, *293, *294 
— , manifolds for, *118 

— speed of gas torch, 83 

— steel risers, 85 

— tests, data on, 86 

— tips, *84 

, Davis-Bournonville, *77 

■ — tools, Messer, *84 

— torch. Airco-Vulcan, *91 
, first, 3 

— • — for ship work, Oxweld, *87, 

82 

, how the, acts, 257 

made by General Welding and 

Equipment Co., *84 

— — , Milburn, *91, 92 

, Eego, *90 

, rivet-head, 80 

, staybolt, *81, 82 

that preheats oxygen, *273, 

*274 

, Torchweld, *92, *93 

, underwater, *94 

— torches, 74, *75, *76, *79 

■ , earbo-hydrogen, 87, *88, *S9 

— — , Davis-Bournonville, *75, *76 

, gas pressures used, 78 

, Imperial, 86, *88 

, machine, *76, 78 

, Oxweld, *79 

— under water, 94 
, depth of, 94 

— unit, typical, *117 

— with a guide, *262 
oxy-hydrogen, 274 

the gas torch, hand, 257, 



*258, *259, *260, *261, 

*262, *263, "266, 267, 269 

"Cut-weld" torch, Milburn, ^91, 92 

Cylinder, amount of acetylene in, 28 

— , automobile, broken, *189 

, welded, *190 

, welding, 164, *165 

— connection adaptors, *103 

— grooved for welding, *188 
— , Liberty, tacking jacket, *233 
— , preheating low-jiressure, *210 

— pressures for acetylene, 27 

— welded, *189 

— welding, a remarkable job of, 

208, *209, *210, *211, *212 

, cost of, ^11 

— , — • low-i^ressure, *211 

— ■, wrecked low-pressure, *209 

Cylinders, acetylene, filling material, 

27 
— , — , temperature of, 27 

— for oxygen and hydrogen, capac- 

ity of, 15 

, weight of, 27 

— , motor, removing carbon from, 

302 
— , sheet-metal, jigs for welding, 

■*227 *228 *229 231 
—,—, welding, *240, *241, *242 

D 

Data on lead burning, 153 

Davis-Bournonville Co., 15, 239, 267, 
272, 279, 280, 286 

cutting machines, *279, *280, 

*281, *282, *284, *285, 
*286, *2S7, *289, *290, 
*292, *293* *294 

— torches, *75, *76 

, gas pi-essures for, 78 

Duograph, 239, *240, *241, 

*242 

hand truck for welding out- 
fit, *35 

" Navy type ' ' acetylene gen- 
erator, 32 

— — positive-pressure acetylene 

generators, 29 



INDEX 



431 



Davis-Boiirnonville underwater cut- 
ting toieh, *94 

water-cooled welding torches, 

*57 

welding torches, 55, *56, *57 

— Acetylene Co., 29 

— acetylene generator, size of, 32 
-^, Augustine, 2 

— electrolyzer cell, 15 

, details of, *17 

Davy, Edmund, 1 

Decarbonizing motor cylinders, 302 

Dentist's torch, *129 

Details of Thermit mold box, *340 
Discovery of acetylene, 1 

oxygen, 9 

Dissociation temperature of water, 4 

Driers, acetylene, Oxweld, size, 40 

Drigas, 5 

— , explosive limits of, 6 

— , method of selling, 5 

— , explosive range, 5 

Drill hole areas, 65 

Drums, sheet-metal, welding, *240, 

*241, *242, *243 
Duograph, the, 239, *240, *2'^1, *242 

E 
Edison Storage Battery Co., 244 

— welding machine for oblong 

seams, *245 
Electric blower tj^e of preheater, • 

*158, *159 
Electrical properties of oxygen and 

hydrogen, 13 
Electrolytic hydrogen, purity of, 14 

— method, principles of, 13 

— oxygen, 10 
, purity of, 14 

— Oxy-Hydrogen Laboratories, Inc., 

24 
Electrolyzer cell, Davis, 15 
-, description of, 18 
,—, details of, *17 
International, *19 
— , current used, 20 
— , details of, *20 
— , principles of, 22 



Electrolyzer cells, space for battery 

of, 25 
■ — , details of Levin, *25 
■ — , Levin, 24 
— , — , principles of, 24 

— plant layout, *22, *23 
Electrolyzers, currents used in, 16 
— , Davis, sizes of, 16 

— , gas capacity of, 16 
Elements, separation of, 173 
Emergency cutting outfit, *122 

— Fleet Corporation tests on 

strength of oxy-acetylene 

welds, *310, 311 
Endothermic acetylene, 3 
Estimating amount of acetylene in 

cylinder, 28 
Eveready instruction book, 150 
Examples of welding jots, 187 

methods, *139 

Expansion allowance on locomotive 

frame, *200 

— and contraction, 154 
Explosive limits of acetylene, 6 
blaugas, 6 

• — • coal gas, 6 

drigas, 6 

hydrogen, 6 

thermalene, 6 

— welding gases, 5 

— range of blaugas, 5 
• drigas, 5 

Equipment of welding shop, 295, 
296, *297, *298, *299, *3G0 

— rules, 305 



Feeding mechanism. Buckeye car- 
bide, 36 

Fery, F. M., 319 

Field of gas-torch welding and cut- 
ting, 7 

Filling rod, using the, 137, *138, 
*147, *148, *149 

— up a hole, 142 

First acetylene pressure generator, 2 

— cutting torch, 3 

— uses of the gas-torch, 3 



432 



INDEX 



First welding gas-torch, 2 

Fixtures for welding, *219, 221, 

*222, *223, *224, *225, *226, *227, 

*228, *229, *230, *232, *233, *234, 

*235, *23G, *237, *238. 
Flame characteristics, *107, *113, 

*114 
— , oxy-acctylene, 3 
—,—, chemistry of, *107, 110 
Fluorides of sodium, potassium, 

aluminum-sodium, 174 
Flow, indicator for gas, 128, *130 
Flux for aluminum castings, 175 

■ brass and bronze, 176 

cast iron, 177 

copper, 180 

Fluxes for welding aluminum, 174 
■ — used in welding, 169 
Fouche, Edmond, 2 
Frame, rudder, ready for welding, 

*201 
—,—, repair, *208 
— , welded locomotive, *199 

— welding, locomotive, *200 

Fuel used in chemical oxygen gen- 
erators, 12 
Furnace for preheating large pinion, 

*372 
— , preheating, on iron table, *156 
— , — , using charcoal, *156 
Fusion and plastic welding with 

Thermit, 319 

— welding, application of Thermit, 

338 
of heavy sections with Ther- 
mit, 333 

G 

Gate patterns for Thermit molds, 

*341 
Gauthier-Ely, 2 
Gear case, repair of, 205, *207 

— teeth, welding, *144, *168 
,— in, *197 

Generating plant, "Navy type" 

acetylene, Bethlehem, *33 
Generator, charging acetylene, 44 
— , details of positive-pressure, *31 



Generator, positive-pressure, sta 
tionary type, *30 

— repairs, acetylene, 45 

— sizes, Oxweld low-pressure, 44 
Generators, acetylene, pressure limit 

of, 30 
— , — , the three types of, 28 
—,—, types, 28, 29 
— , Davis acetylene, sizes and 

weights, 37 
Gages for gas j)ressures, 95, *96, 

*98, *99, *100, *101, *102 
Galvanized iron welding, 186 
"Gas Torch," 1 
Gas, acetylene, amount from pound 

of carbide, 29 

— capacity of Davis electrolyzers, 

16 

— consumption in cutting, 83 
lead burning, 153 

-of carbo-hydrogen cutting 

torches, 84 

— cutting torches, 74, *75, *76, *79 

— flow indicator, 127 

— pressure in lead burning, 153 
regulators, 95, *96, *98, *99, 

*100, *101, *102 
— - — used in Thermalene welding 
torches, 72 

— pressures for cutting torches, 78 
Davis-Bournonville welding 

torches, 59 
Imperial oxy-hydrogen 

torches, 62 

three-way welding 

torches, 63 

Oxweld torches, 68 

— — welding torches, 68 

— Prest-0-Lite welding 

torches, 61 

— Thermalene welding, 72 

welding torches, 59, 61, 

62, 63, 68, 72 
used in cutting, 83 

— torch, field of, 7 

welding and cutting outfits, 

116, *117, 119, *120, *122, 
*126, *127, *128, *129 



INDEX 



433 



Gas toreli welding speed, 61, 68 

— torches used for welding, 54, *55, 

*56, *57, *60, *62, *66, *67, 
*G9, *70, *71, *72 
Gases, calculating amount of weld- 
ing, 63, 64 
— , explosive limits of, 5 
— , ignition temperatures of, 6 
Gasometer, Oxweld, size and capac- 
ity, 40 
General Electric Co., 292 

— Welding and Equipment Co., 84 
welding torch, *60, 

61 
Generator, Oxweld acetylene, port- 
able tj-pe, *39 
Generators, Oxweld duplex, *43 
— , — , sizes of, 40 
— , Thermalene, 45, *46, *51, *52, 

53 
German silver welding, 186 
Gold welding, 186 
Goldschmidt, Hans, 317 

— Thermit Co., 318 

Goggles for gas-torch work, 120, 

*121 
Grating, welding, 155, *162, 163 
Great Western cutter, *288 

Cutting & Welding Co., 279, 

288 
Grinding machine for rail work, 400, 
*401 

, use of, 187 

Grooved cylinder ready for welding, 

*188 
Grooving with an air chisel, *187 
Guide for cutting, *262 
— , yoke welding with Thermit, *352 
Guides for welding, *310 

H 

Hales, Stephen, 9 
Hastings, G. A., 215 
Heat of Thermit, 318, 319 
— - units in acetylene, 3 
Heating, improper, *163 

— torches, *157, *158, *159 
, using, *157 



Helmbacher Eolling Mill Co., 416 
Henderson Motorcycle Co., 227 
High speed tips, welding, 213, *214, 

215, *216, *217, *219 
welded to machinery steel 

with Thermit, 418, *419, 

*420 
History and nature of Thermit, 317 
Hole, filling a large, 176 
— , blowing a, through a plate, *261 
Holder, crucible, for locomotive 

work, *355 
Holding the gas torch, *132 
Holes, filling, 142 
Holograph cutting machine, *285 
Hooks, making large, *265 
Hose, color of, 101 
Howard, H., 201 
Hydrate Engineering Corp., 127 
Hydrex gas flow indicator, 128, *130 
Hydrogen and acetylene flames 

compared, 13 

oxygen flame, heat of, 13 

, rate of electrolytic pro- 
duction, 16 

— by the electrolytic method, 13 

— compressed air flame character- 

istics, *114 

— cylinders, pressure of, 15 
, size and weight of, 15 

— electrolytic, purity of, 14 
— , explosive limits of, 6 

— gas, 4 

— , ignition temperature of, 6 
- — , specific gravity of, 6 



Ignition temperature of acetylene, 6 
city gas, 6 

— — — gases, 6 

Igniting Thermit, 317, 326, 344 
Illinois Central E. E. shops, 421 
Illuminating gas, 5 
Imperial Brass Mfg. Co., 86, 259, 
260 

— cutting torches, 86, *88 

— decarbonizing outfit, *304 



434 



INDEX 



Imperial preheating torch, *158 

— three-way gas outfit, *111 
welding torch, 63 

— welding torch, *62, (53 
Improper heating, *163 
Injector type gas torch, 54, *55 
Inlet pipe, Liberty motor, welding, 

*234 
Insert rail welds, 392, *393, *396, 

*397, *398, *399 
Instructions for lead burning, 150 
International cell, capacity of, 20 
-- cells, group of, *21 

— Oxygen Co., 19 
generator, 18 

Ireland & Mathews Mfg. Co., 236 
Iron table with firebrick top, *156, 
*159 



Jaw, locomotive frame, welding 

with Thermit, *348 
Jeweler's torch, *129 
Jig for welding tool tips, *219 
Jigs and fixtures for welding, *219, 
221 *222 *223, *224, *225, *226, 
*227, *228, *229, *230, *232, *233, 
*234, *235, *236, *237, *238 
Jottrand oxygen jet cutting patent, 3 
Journal of Acetylene Welding, 176 

K 

Kautny, 4 

Keeping track of costs, 302 
Keithley, F. N., 369 
Kerf of a cutting torch, 75 
Kerosene preheater, *157 
Kettle, welding a large, 192, *193 
Kinds of Thermit, 320 
Kirk, J. W., 274 

Knuckle machine repaired with 
Thermit, *419 



Ladle hooks, making large, 265 
Lap joints, lead, 151 
Lathe bed repairs, *195 



Lavoisier, 9 

Layout of acetylene plant, ' ' Navy 
type, *34 

welding shop, 295, *297 

Lead burning, 125, 126 

data, 153 

, gas consumption in, 153 

, — pressure used in, 153 

— — instructions, 150 

— — outfits, *126 

• sticks, or rods, 151 

— welding or "burning," 181 
Leaks, testing for, 105 

Learning to weld with a gas-torch, 

131 
Le Chatelier, 2 
Le Ehone motor, 237 
Levin, I. H., 24 

— generator for oxygen and hydro- 

gen, 24 
Liberty motor manifold work, *236, 
*237, *238 

work, 231, *233, *234, *235 

Lighting low-pressure torch, Oxweld, 

109 

— the torch, 104, 109 
Lincoln Motor Co., 231 
Linde Air Products Co., 9, 312 
— , Carl, 2 

— process, 2 

Lining Thermit crucible, *333, 334 
Links, chain, building up, 205, *207 
Lithium chloride, 174 
Liquid air process, oxygen by the, 9 
Lloyd tube welding patent, 250 
Locating cracks, 364 
Locomotive crosshead, welding with 
Thermit, *351 

— frame, heating zones on, for 

Thermit welding, *347 

— — leg, welding, with Thermit, 

*348 
splice, welding with Thermit, 

*349, *353 
, welded, *199 

— — welding, *200 
with Thermit, *347 

- — mud ring with Thermit, *350 



INDEX 



435 



Locniiiotivr vnokcr shaft, weldini;- 
with 'riuMiiiit, ''''.'i5'2 

— wheel weliling with Thermit, *o54 
Low-pressure acetylene generators, 

operation of, 41 
torch, lighting the, 109 

— — welding torch, 54, *55 
torches, Oxweld, *66, *67, 

*69, *7() 
Ludwick, Herbert V., 218 

M 

Maehine cutting torches, *76, 78 

— for circular seams, *244 

facing pipe ends, 322 

welding oblong seams, *245 

— tools, welding, 193, *194, *195, 

*196 
— , torches for welding, *253 

— welding torches, "57, *64, *7() 
Machinery steel welded to high speed 

steel with Thermit, 418, *419, *420 
Machines for cutting, *278, *279, 
*280, *281, *282, *283, 
*284, *285, *286, *287, 
*288, *289, *290, 291, *292, 
*293, *294 

welding, 239, *240, *241, 

*242, *243, *244, *245, 
*246, *247, *248, 249, *250, 
*251, 252 
Macleod Co., The, 11 

— Co. 's cai-bide feed, 36, *38 
Magnesia stone thimbles for Ther- 
mit crucibles, *333, 336 

Magnesium powder for igniting 

Thermit, 317 
Magnetograph cutting maehine, 284, 

*285 
Making allowance for expansion and 

contraction, 154 
Malcher, L. M., 208 
Malleable iron welding, 181 
Manganese dioxide, uses of, 10 

— steel welding, 186 

Magnesia tar used for Thermit 
crucible, 334 



Manifold welding, *226, *227, *230, 

*232, *236, *238 
Manifolds, *118 
Martin, T. O., 421 
McCormack, calculations of, for 

specific gravity, 6 
McManamy, Frank, 309 
Melting points of various metals, 

170 
Messer cutting tools, *84 

— Mfg. Co., *70, *71, 82 

— welding torch, *70 

Metals and Thermit Corporation, 

318, 422, 425 
— , commonly welded, properties of, 

170 
Metropolitan Railway of Paris, rails 

welded for, with Thermit, 411 
Miller, S. W., 162 
Modified Clark joint, *407, *408, 409 
Moisson, H., 1 
Mold for pipe welding, *324, *325, 

*328 
welding high speed and ma- 
chinery steel with Thermit, 
"419, *420 

— box, details of Thermit, *340 
— , ramming Thermit, 340 

— , Thermit, for heavy sections, *33S 
Molds, Thermit, *323, *324, *325, 

*328, *338, *342, *348, *349, 

*350, *367 
— , wax-pattern, *338, 339 
Monel metal welding, 183 
Motor case welding with Thermit, 

*410, Mil 

— cylinder welding, 164, *165 
Motorcycle manifold welding, *226. 

*227 
Movement for welding, *133, *137, 

*147, *148, *149 
Mud ring, locomotive, welding with 

Thermit, *350 
Musick, W. J., 416 

N 
Nail machine repaired with Ther- 
mit, *418 



436 



INDEX 



Napolitan, F. J., 267, 269 
Nashville, wheel shaft weld on, *386, 

389 
National Safety Council rules for 

gas-torch users, 305 
' ' Navy type ' ' acetylene generator, 
32 

generators, size of, 35 

— plant layout, *34 

Necks on pinions, welding new, 374, 

*376, *378, *380, *381, *382, *384 
Neutral flame, 3 
New York Shipbuilding Yards, work 

in, *281 
Nickel steel welding, 186 

— welding, 183 
"Nicking" billets, 262 

Nitrogen and oxygen, separation of, 

10 
■ — , boiling point of, 10 
North American Mfg. Co., 160 

— — ■ preheater, *159 

O 

Olympia, welded anchor davit of, 

*385, 389 
Operation rules, 306 
Osceola, wheel shaft weld on, *387, 

390 
Outfits for welding and cutting, 116, 
*117, 119, *120, *122, *123, *126, 
*127, *12S, *129 
Outlet pipe. Liberty motor, weld- 
ing, *235 
Oval hole cutting machine, *288 
Oven, Cooling, Wiederwax, *161 
Oxidation and conductivity, 169 
Oxide, how to deal with, 171 
Oxweld Acetylene Co., 150, 208, 209, 
236, 247 

— — Co.'s portable pressure-type 

acetylene generator, 36, *39 
• — cutting data, 83 
■ — cutting machine, *278 

torches, *79 

• — duplex acetylene generators, *43 

— gasometer, size and capacity, 40 



Oxweld low-pressure generator sizes 

and capacities, 44 
torch, *66, *67, *69, *70 

— outfit, a complete, *123 

— preheating torches, *157 

— pressure type acetylene gener- 

ators, 40 

— regulators, 95, *96, 97, *98, *99, 

*100 

— rivet-head cutting torch, *80 

— sheet-metal welding torch, *69 

— torches, gas pressures for weld- 

ing, 68 

— water-cooled welding torches, 

*69, *70 
Oxy-acetylene flame characteristic, 

*107 
temperature, 3 

— welds, strength of, 311 
Oxygen-acetylene-hydrogen welding 

pressures, 63 
— , amount obtained from cholorate 
of potash, 10 

— and hydrogen electrolyzer plant, 

*22 
rate of electrolytic pro- 
duction, 16 

— — nitrogen in the air, 9 
— , separation of, 10 

— by the electrolytic method, 13 
liquid air process, 9 

— , chlorate of potash process, 10 

— cylinder pressure, 9 

— cylinders, sizes of, 9 
— , discovery of, 9 

— , electrolytic, purity of, 14 

— generator, chemical, *11 
, International, 18 

— illuminating gas flame character- 

istics, *114 

— jet cutting patent, 3 
— , Linde method patent, 2 
— , liquid, boiling point of, 10 

— manifolds, *118 
— , purity of, 10 

— regulator, details of, *96, 97 
— , using, for carbon burning, 302 



INDEX 



437 



Oxygraph cutting machine, 292, 

*293, *294 
Oxy-hydrogeu cutting, 274 

— cutting pressures, 86, 87 

— flame characteristics, *113 
, temperature of, 4 

— for cutting, 13 

— welding flame, uses of, 13 
pressures, 62 

torch, *71, *72 



Patents on Thermit, 317 

Patterns for Thermit mold gate and 

riser, *341 
Phelps, C. C, 236 
Picard, 2 

Pinion, a Thermit welded, *373 
— , preheating, for Thermit welding, 
*371 

— teeth, replacing with Thermit, 

365, *367 
Pinions, welding new necks on, 374, 
*376, *378, *380, *381, *382, *384 
Pipe facing machine, *322 

— mold for welding vertical pipe, 

*328 

— welding, *222, 223, *228 

— — materials, *323 

mold, *324, *325, *328 

outfit, 324 

with Thermit, cost of, 424 

— welds, cost of Thermit, 329 

, strength of, Lindc tests, 312 

Pit for Thermit welding roll and 

pinion necks, *376 
Pittsburgh Steel Co., 418 
Planer bed repair, *194 
Plant layout for electrolyzers, *22, 

*23 
Plastic and fusion welding with 
Thermit, 319 

— process welds, 322 
Plate; speed of welding, 204 
Phimley, Stuart, 267 

Pneumatic chisel for welding work, 

*187 
Pods, building up, 205, *206 



Poison-gas containers, welding, *230, 

*232 
Portable electric blower type of pre- 
heater, *158, *159 

— pressure type acetylene gener- 

ator, 36 
Position for cutting, *258 
Positive-pressure acetylene gener- 
ator, 29 

— ■ • , first one made, 29 

Potassium bisulphate, 174 

— chloride, 174 

— fluoride, 174 

— hydroxide, uses of, 17 

— sulphate, 174 

Pouring Thermit into pipe mold, 
*328 

Preheater, electric blower type of, 
*158, *159 

— , North American, *159 

—, Tyler, 158 

— , Wiederwax, *161 

Preheaters, *156, *157, *158, *159, 
*161 

— , gasoline and kerosene, for Ther- 
mit work, *423, 424 

Preheating and welding method, 
*191 

— aluminum, 175 

— for Thermit welding, *371, 42'1, 

*423 
rail welds, 397, *399 

— motor cylinders, *165 

— Thermit mold, 343 

— torches, Oxweld, *157 

— zones indicated, *155, *162, *163, 

*165 
Preparing Thermit mold, 343 
Pressure gages, gas, 95, *96, *97, 

*98, *99, *100, *101, *102 
— , gas, for welding torches, 59, 61, 

62, 63, 68, 72 

— of carbo-hydrogen for cutting, 89 

gas in lead burning, 153 

oxygen in cylinders, 9 

Pressures, gas, in cutting, 83 

• — • used for underwater cutting, 94 
in three-way gas system, 87 . 



438 



INDEX 



Prest-0-Lite tool welding practice, 

*216 
— welding torch, 58, *60 
Priestly, 9 
Production of oxygen, 9 

■ welding gases, 9 

Propeller blade beveled for welding, 

*188 
Properties of metals commonly 

welded, 170 
Pryor, Frederick L., 329 
Paget Sound Navy Yard, 94 
Pulley, welded in 12 places, "198, 

199 
- — , welding, *163 
Pump, building up worn parts of, 

205, *206 
Punch press frame repairs, *194, 

*195, *196 
Purifier, acetylene, Oxweld, size, 40 
Purity of oxygen, 10 
"Putting on" metal, 143 
Pyrograph cutting machine, *289, 

*290, 291, *292 



Quantity of Thermit to use, 345 

wax used for Thermit weld 

ing, 346 

R 
Rack-feed cutting machine, *280 
Radiagraph cutting machine, 280, 

*281 
Radius cutting attachment, *263 
Rail bonding, 204, *205 

— grinding machine, 400, 401 

— joints, compromise, welding, 403, 

*405 

— preheater for heating four joints 

at once, *423 

— specifications for difference in 

height, 391 

— welding for electric systems, 391 

— weld patterns, *394, *395, 404 

— welds, insert, 392, *393, *396, 

*397, *398, *399 
Railograph cutting machine, *282 



Railroad Thermit, composition of, 

321 
Railway Administration welding 

rules, 309 
— , K. C. Southern, 200 
Raleigh Iron Works Co., 414 
Ramming Thermit mold, 340 
Ecactions, 416 
Reamer, inserted blade, made by 

Thermit process, 419, *421 
Rego cutting torch, *90 

— welding torch, 64, *66 
Regulator attached to gas-cylinder, 

*103 

— connection adaptors, *103 
Regulators, acetylene, *100, *102 
— , gas, Davis-Bournonville, *101, 

*102 
—, Oxweld, 95, *96, *97, *98, *99, 

*100 
—, oxygen, 95, *96, 97, *98, *99, 

*101 
Restrained weld, *162 
Richards, Joseph W., 318 
Richardson, Capt. D., 144 
Riser patterns for Thermit molds, 

*341 
Risers, cutting steel, 85 
Rivet cutting, *261 
Rivet-head cuttmg-torch, Oxweld, 

*80 
Rochester Welding Works, 162 
Rocker shaft welding with Thermit, 

*352 
Rod, size of, for steel, 184 
— , using the welding, 137, *138, 

*147, *148, *149 
— , welding, for cast iron, 178 
Rolled aluminum, purity of, 173 
Roller, welding sheet-metal, *227 
Roll neck welding with Thermit, 

*367 
— pods, building up, 205, *206 
Rolling mill base repaired with 

Thermit, *418 
Rolls and pinions, welding new necks 
on, 374, *376, *378, *380, *381, 
*382, *384 



INDEX 



439 



Rolls, arrangement of, for tube weld- 
ing, 251, *252 

Koot & V'auilervoort Engineering 
Co., 218 

Roulleau, M., 145 

Rules, equipment, 305 

— for operation, 306 

welding, U. S. Railway Ad- 
ministration, 309 

Rudder frame ready for welding, 
*201 



repair. 



208 



Rules, safety, for gas-torch workers, 

305 

S 
Safety rules for gas-torch workers, 

305 
Schneider works, cutting heavy plate 

in, *283 
Seam, circular, welding, 244 

— contraction, allowing for, *135, 

*136, *137 
— , oblong, welding, *245 
Separation of elements, 173 
Shaft welding, *222, 223 

with Thermit, V-blocks for, 

*361, 362 
Shear arm, welding, *167 

— jaw burned on with Thermit, 

*415 
Ship plate cutting, *263 
Shop layout, 295, *297 
Silver, German, welding, 186 

— welding, 186 

Sizes of oxygen cylinders, 9 

Smith, Elmer H., 274 

— , F. M., 247 

Sodium bisulphate, 174 

— chloride, 174 

— fluoride, 174 

— hydroxide, use of, 10 

— — , uses of, 17 

— sulphate, 174 

Sawing oft" end of roll neck previous 

to Thermit welding, *375 
Special steel welding, 185 
Specific gravity of gases, 6 

— heat of various metals, 170 



Speed, carbo-hydrogen cutting, 89 

— , cutting, of gas torch, 83 

— , machine, for welding tubes, 255 

— of cutting, 263, 273 

— — — steel risers, 85 
underwater, 94 

— ■ ■ — ■ machine cutting, 280, 283, 
284, 286, 289, 291, 292, 294 

— ■ ■ — ■ oxy-hydrogen cutting, 275, 
276 

plate welding, 204 

— — welding steel and sheet iron 

cylinders, 231 

— with a gas torch, 61, 68 

Splice, locomotive frame, welding 

with Thermit, *349, *353 
Spreader disk for tube welding, 

*251, *252 
Square liole cutting machine, *288 
Standard Parts Co., 417, 419 
Starting a cut, *258, *259 
Staybolt cutting torch, Oxweld, *81, 

82 
Steel, high speed and alloy, welding, 
185 

— — — , welding, 213 

— , Thermit, composition of, 318 

— to cast iron, 179 
copper, welding, 180 

— welding, 183 

Sternpost welds, *387, *388, *389 

Stone & Webster Corp., 92 

— , Geo. M., 416 

Storage battery burning, 152, 153 

Straight-line cutting machines, *278, 

*279, *283 
Strength of oxy-acetylene welded 
pipe, 312 

welds, 311 

Thermit welds, 318, 329, 331 

— — welded tank, 203 
Sulphates of sodium and potassium, 

174 

T 
Table for welding work, *221 
— , iron, with firebrick top, *156, 

*159 
Tables, welding, *300 



440 



INDEX 



Tank and hose colors, 101 

—, welded, *203 

— , — , strength of, 203 

— welding jig, *229, 231 
Tapping Thermit crucible, *334 
Temperature of oxy-acetyleue tlanie, 

3 

oxy-hydrogen flame, 4 

■ Thermit, 318, 319 

Thermalene flame, 3 

Tensile strength of various metals, 

170 
Tested, kinds of welds, *310 
Testing for gas leaks, 105 
Tests of Welding Committee, *310, 

311 
Thermalene, advantages of, 52 

— cartridge, 46, 47, *48, 50 

— Co., 5, 45, 244, 246 
— , composition of, 45 
— , discoverer of, 5, 45 

— , explosive limits of, 6, 52 
— , first description of, 45 

— flame, temperature of, 3, 51 

— gas welding pressures, 72 

— generators, 41, 45, *46, *51, *52, 

53 
— , makers of, 5, 45 
• — , production of, 49 
— , properties of, 51, 52 
— , specific gravity of, 6 
Thermit additions, use of, 400 
— , amount of; used for roll and 

pinion work, 379 
— , — to use, 345 

— crucible, 333 

— crucibles, details of, *333, 337 
— , history of, 317 

— , igniting, 317, 326 
—, kinds of, 320 

— molds, *323, *324, *325, *328, 

*338, *342, *348, *349, *350, 
*367 

— patents, 317 

— pipe welding, 322 

— plain, railroad and cast-iron, 320 

— plastic-process welds, 322 

— reaction, 318 



Thermit steel, composition of, 318, 

320, 321 
• — , temperature of, 318, 319 
— , the two methods of using, 319 

— welding ' ' don 'ts, ' ' 353 

— welds, strength of, 318, 329, 331 
Theoretical proportions of oxygen 

and acetylene, 2 
Thimbles, magnesia stone, for Ther- 
mit crucibles, 333, 336 
Third rail welding, *409, 411 
Three-way gas system, pressure used 
m, 87 

— welding torch. Imperial, 63 

Tip, preparing to weld, *214, *216, 

*217, *219 
Tips, cutting, *77 

— for welding torches, *58, *60, 

*67, *70, *71, *72 
— , welding on high speed steel, 213, 

*214, 215, *216, *217, *219 
Tire, welding, for truck, 190, *192 
Tool welding, 213, *214, 215, *216, 
*217, *219 

practice of Eoot & Vander- 

voort Engineering Co., *217, 
218 
Tooth pattern, making a wax, *367, 

368 
Torch arrangement on welding ma- 
chine, *241, *243, *244, *245, 
*251, *252 
— , carbon electrode and oxygen jet, 

*274 
— , cutting, action of, 257 
— , — With the hand, 257, 
*259, *260, *261, 
*263, *266, 267, 269 
— , gas and air preheating, *158 
— , how to hold the gas, *132 

— motion, *133, *137, *147, *148, 

*149 
Torches, combination for welding 

and cutting, *91, *92, *93 
— , cutting, 74, *75, *76, *79 
—, heating, *157, *158, *159 
— , water-cooled machine, for weld- 
ing, *253 



*258, 
*262, 



INDEX 



441 



Torchwold cutting torch, *93 

— Equipment Co., 93 

Trouble, sources of in welding, 140 
Truck, car, welded with Thermit, 

*412 
— , motor, welding, *192 
Tube, samples of welded, *254 

— welding machines, *246, *247, 

*248, 249, *250, *251 
Tyler, Mfg. Co., 159 
Types of acetylene generators, 28 

welding torches, 54, *55 

Typical oxy-acetylene cutting unit, 

*117 
Tyler, preheater, *158 

U 

United Railways and Electric Co., 

Thermit welded joints for, 409 
Universal cutting machine, *292 



V 

V-blocks for shaft welding with 

Thermit, *361, 362, *363, *364 
Valves, back-pressure, *124, *125 
Vaporization of substances, 172 
Vanadium steel welding, 186 
Vautin, Claude, 317 
Vertical pipe, welding mold, *328 
— welds, 142 
Volumes of oxygen and acetylene 

used, 3 
oxy-hydrogen, 4 



W 

Waclark "Wire Co., 417, 418 
Water-cooled cutting torches, Davis- 
Bournonville, *76 

welding torches, Davis-Bourn- 

onville, *57 

torches, Oxweld, *69, *70 

— , dissociation of, 4 
— jacket, tacking, for Liberty 
motor, *233 



Wax-pattern molds for Thermit 
welding, 338, *339 

— tooth pattern, *367, 368 
Weiderwax, preheater, *161 
Weight of oxygen cylinders, 10 

Thermit apparatus, 422 

various metals, 170 

Weld, restrained, *162 
Welding aluminium, 173 

- — • and cutting, field of, 7 
outfits, 116, *117, 119, 

*120, *122, *126, *127, 

*128, *129 
preheating method, *191 

— backward, 144, *147, *148, *149 

— Committee tests, *310, 311 
Welding Engineer, 200, 213, 274 

— gases, estimating amount, 63, 64 
, explosive limits of, 5 

— jigs and fixtures, 221 

— jobs, examples of, 187 

— machines, 239, *240, *241, *242, 

*243, *244, *245, *246, *247, 
*248, 249, *250, *251, 252 

— motion, *133, *137, *147, *148, 

*149 

— outfit on hand truck, *35 

— ■ portions for Thermit welding of 
rectangular sections, 345 

— rod, using the, 137, *138, *147, 

*148, *149 
• — shifts on large work, 213 

— shop layout, 295, *297, *298, 

*299, *300 

— speed with a gas torch, 61, 68 

— torch, Airco-Vulcan, *91 
, first, 2 

• — - — , low pressure, 54, *55 

, Messer, "70, *71 

, Milburn, *91, 92 

made by General Welding & 

Equipment Co., *60, 61 

, positive-pressure, 54, *55 

, Prest-0-Lite, 58, *60 

, Rego, 64, *66 

— — , Thermalene, *71, *72 

— torches, 54, *55, *56, *57, *60, 



442 ■ INDEX 

*62, '66, *67, *69, *7(), *71, Wheel, driviug, welding with Ther- 

*72 mit, *354 
Welding torches, Davis-Boiunonville, — shaft welds, *;)86, *3S!) 

55, *56, *57 White metal welding, 186 

, Imperial, *62, 6;! IVillium Ilciiri/ Mack, Sternpost 

, machine, *57, *69, *70 weld on the, *3S8 

, Oxweld low-pressure, *66, Willson, T. L., 1 

*67, *69, *70 Wohler, Frederick, 317 

, t^-pes of, 54, *55 Wolf, Linus, 5, 45, 244 

— various metals, 169, 173 Wrought iron welding, 186 
Wolds, l)uilt-up, *141, 142 



